Pond repair question        5/21/15 Hi Bob, <Wendell> I recently bought a property in northern Vermont, neglected for many years, with a large (1/2 acre or about 20,000 sf) bitumen asphalt pond. <Oooh, olde school> The pond should be around 7' deep but has a leak at roughly 4'6". There is a drain valve in a manhole which I tested and works fine. My plan was to drain the pond, either fully and muck it out, <How?> or enough to expose the leak cracks and then fill and seal them. <With...?> I am reluctant to fully drain it at the moment as there are many frogs and salamanders breeding - and I think one snapping turtle which I'd like to get rid of. <Yes; I would> There are many cracks around the sloped edge with organic material growing out of them. Fortunately, a metal snow shovel seems to clear off most of it. <I'd consider making a shotcrete (and color) berm... with anchored pencil rod re-bar and mesh (chicken wire likely)> What would you recommend patching it with? <Maybe more asphalt emulsion... Henry's or such... But... really... best to have the soil tested... IF you want a more permanent improvement... See WWM re liners...> My thought was to gouge out the cracks and fill with either hydro-cement or asphalt/bitumen. <Worth trying> Is there a plastic or polymer solution to this? <Not as far as I know; no> During Feb/Mar, I measured the surface ice to be 16"+, so freeze/thaw is another problem. <Yes... a few approaches to this as well... the slope and berm...> See pics attached... Many thanks, Wendell Anderson <Let's keep chatting till you're aware of your choices here. Bob Fenner>

Re: Pond repair question        5/21/15 Hi Bob, Thank you. See below. <Uhhh; a mess for others to read through> > Subject: Pond repair question > Hi Bob, > <Wendell> > I recently bought a property in northern Vermont, neglected for many years, > with a large (1/2 acre or about 20,000 sf) bitumen asphalt pond. > <Oooh, olde school> > The pond should be around 7' deep but has a leak at roughly 4'6". There is > a drain valve in a manhole which I tested and works fine. My plan was to > drain the pond, either fully and muck it out, > <How?> {was thinking to drain it fully and rake/shovel it out) <<DO look into buying or renting a trash-pump... diaphragm type if there's much in the way of larger solids... And I suspect there will be further damage from entering the pond>> > or enough to expose the leak cracks and then fill and seal them. > <With...?>(Thoroseal WaterPlug in cracks, cover in Thoroseal or bitumen driveway sealer, Henry's roof sealer?) <<NEED to know if the damaged area is expansive... i.e. if it's moving at all. If so the Thoro products won't work; nor asphaltous material if much wet, flexible.... might try a patch... of roofing material AND the Henry's... will require a few dry days to dry the pond, dry the repair>> > I am reluctant to fully drain it at the moment as there are many frogs and > salamanders breeding - and I think one snapping turtle which I'd like to > get rid of. > <Yes; I would> > There are many cracks around the sloped edge with organic material growing > out of them. Fortunately, a metal snow shovel seems to clear off most of  it. > <I'd consider making a shotcrete (and color) berm... with anchored pencil > rod re-bar and mesh (chicken wire likely)>(I think this will be Plan B - assume you mean just the top edge to below present waterline where leak is, will it adhere to the underwater area after draining enough to expose and dry it) (I walked it and there is roughly 500' of perimeter x 6'-8' of exposed berm, about 30" in elevation depth) <<Yes to over the existing edge throughout>> > What would you recommend patching it with? > <Maybe more asphalt emulsion... Henry's or such... But... really... best to > have the soil tested... IF you want a more permanent improvement... See WWM > re liners...>(I assume a 1/2 acre liner would be most costly? - Plan C perhaps) <<I'd count on a half dollar to a dollar a square foot... for the whole project... IF the soil can be mixed w/ an impervious clay... might hold, be cheap>> > My thought was to gouge out the cracks and fill with either hydro-cement or > asphalt/bitumen. > <Worth trying>(Plan A, as above with ThoroSeal plug) > Is there a plastic or polymer solution to this? > <Not as far as I know; no> > During Feb/Mar, I measured the surface ice to be 16"+, so freeze/thaw is > another problem. > <Yes... a few approaches to this as well... the slope and berm...> > See pics attached... > Many thanks, > Wendell Anderson > <Let's keep chatting till you're aware of your choices here. Bob Fenner>(Thanks again...) <<Cheers, BobF>>

Spring fed water feature       4/4/15
Hello, I've been looking everywhere online and your web sight seems to have the most diverse information and consequent knowledgeable replies that my help me with my unique situation. The following is a description of my water feature.
<Let's have it!>
I live in a hilly wooded area with natural springs popping out in every ravine. The original homeowner dammed the ravine nearest and about 30 feet higher in elevation than the house and ran a 1.5" pipe from the pond behind the dam to a waterfall and small brook he built on the back of the house.
The waterfall is 5' tall and 4' wide. It fills a small 2 foot wide "L" shaped pond 1' deep, the short leg of the "L" is in front of the waterfall and the long leg is 8'. The flow out of the "L" shaped pond overflows to a 2' wide shallow brook that continues 30' flowing gently down hill back into the ravine. These features were all constructed with natural stone laid in concrete.
<No liner underneath....>
The waterfall and the brook sides are built with rounded stones and the pond and brook floors were built with flagstone. This was all built in the 1970's. The last 2 years I've experienced severe frost heave on posts supporting an outdoor bar I built 15 years ago that is beside the water feature.
<Ohh...>
With it being spring feed, running continuously year round a leak is not obvious and being in place for over 40 years there is a tremendous amount of calcified growth, especially on the waterfall. I'm planning to install a French drain between the bar and the water feature to control the spring leakage. Ideally I'd like to install a liner but that's not practical. So I've diverted the spring flow away from the waterfall and brook and I'm jack-hammering off the calcified waterfall growth to get back to the original stone. After that I'll start looking for leaks.
<Mmm; not likely productive>
With all the above background information what will be the best method to seal the leaks and realizing that I'll never be leak free do you think the French drain concept will interrupt the sub-surface water movement to eliminate the bar structure post supports from frost heaving.
Thanks
Jeff Dieterle
Northern Indiana
<Thank you for writing; and your kind initial words. The leakage can really only be addressed in a permanent way by applying the liner.... As you'll see it is VERY hard to locate leaks about rock/concrete... and even small joints twixt them can result in huge seepage of water. I do think your diversion of water and removal of calcification is worthwhile... but almost assuredly you'll have to lay in a liner anew a replacement feature (rather than using the existing), as the current is not likely to lend itself to modification. Bob Fenner> 
Re: Spring fed water feature       4/6/15
Thanks for the quick reply. There is no liner behind the waterfall or under the brook and I realize that a liner the only way to stop leakage.
<Yes; the only assured way>
I'm not sure how I would rebuild the waterfall with the liner behind it and replicate the original design.
<Won't be original... if possible, practical, building over the existing, using it as part of the structural trough is the route to go... extending the liner as the stream>
I'm still jack-hammering the overgrowth but it appears that a single vertical row of rounded stone was laid with
concrete (instead of mortar) and tight against the block wall behind the waterfall.
<Very typical in time failing. Bob Fenner>

Leaking Pond /Darrel (!)
Dear Bob,
A year ago I corresponded with you (and appreciated your helpful answers!)
about building a pond. I followed your advise and hired somebody to do the mixing of concrete. He used a bit of concrete on the walls over chicken wire, but then covered the bottom and walls of the pond with Multiset modified thin-set mortar for floor and wall tiles (by Custom Building Products company).
The pond is slowly leaking and I believe that water permeates the mortar as it is probably not designed for continuous exposure to water and under pressure to boot. I can see a wet strip of mortar above the water line where the water presumably seeps in by capillary action. Is there anything I could do to make the surfaced waterproof? Preferably cover/paint it with something rather than using unit for which I would need special equipment.
I would prefer to do it myself as I do not trust the guy who did it anymore. (In addition to the leakage, there are other reasons for not dealing with him anymore.)
Many thanks for your advise...I certainly hope you can come up with some do-able solution. Best wishes, Zuzana
<Hi Zuzana>
<I'm not Bob so I left your email specifically for him -- but I HAVE had a leaky pond, so I thought I'd jump in {pun intended!}>
<I've built a number of ponds over the years and I've encountered many others in various forms of disrepair and I'm vary familiar with concrete-over-chicken-wire construction and the leaks that come along with that.>
<After you drain the pond you have to do a close inspection of the entire pond for structural problems. What I'm saying is that no coating that you're going to apply without special equipment is going to fill large gaps or fill any gaps that flex or expand. If you have any structural problems or cracks they have to be fixed the old-fashioned way, which is to say grinding them out and using a good quality cement (like Quick-crete sold at building supply stores) to get a proper structure.>
<In connection with that you have to prepare the surface for whatever coating you're planning to use. This usually involves a scrub with diluted muriatic acid to clean and etch the surface. No special equipment, but it's messy and stinky and you need to rig up some ventilation because you don't want to breath the fumes.>
<Just link in painting ... preparation is everything. The more time you spend in preparation the more time you'll spend ENJOYING your pond rather than draining and repairing it. What I mean is... when you think you have the surface prepped perfectly... work on it some more.>
<Now this brings us to the faith-based portion of the job. I have heard for years about a wonderful product called Thoroseal and I've heard many a professional pond builder rave about it. It's never worked very well for me. I've used a gray Thoroseal paint to seal a concrete waterfall and it seemed to work fine and lasted about 5 years.>
<What I used - and I'm only giving you my opinion {worth every penny you're paying for it} is Nelsonite PoolPoxy. If you use PoolPoxy2 you'll have a durable finish that will last 10 years. If you use PoolPoxy Hi-build over Nelsonite Primer the people who buy the house after the people you sell it to will probably have to pay someone to break it up & haul it away>
<If you go this way - or even go the Thoroseal way - follow the manufacturer's instructions to the letter & in the slightest question contact them for clarification. I'm sure Bob will agree that when it comes to most complaints about coatings, most include "well, I skipped that step and I short cut on this other step...">
<Best of luck - Darrel>
Leaking pond /RMF
Dear Bob,
A year ago I corresponded with you (and appreciated your helpful answers!) about building a pond. I followed your advise and hired somebody to do the mixing of concrete. He used a bit of concrete on the walls over chicken wire, but then covered the bottom and walls of the pond with Multiset modified thin-set mortar for floor and wall tiles (by Custom Building Products company).
<Sounds good thus far; but; where's the liner here?>
The pond is slowly leaking and I believe that water permeates the mortar as it is probably not designed for continuous exposure to water and under pressure to boot. I can see a wet strip of mortar above the water line where the water presumably seeps in by capillary action. Is there anything I could do to make the surfaced waterproof?
<Yes; will necessitate emptying, cleaning, likely acid/bleach washing and drying the basin first>
Preferably cover/paint it with something rather than using unit for which I would need special equipment. I would prefer to do it myself as I do not trust the guy who did it anymore. (In addition to the leakage, there are other reasons for not dealing with him anymore.)
Many thanks for your advise...I certainly hope you can come up with some do-able solution. Best wishes, Zuzana
<Please read here:
http://wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm
scroll down to Water Feature Repairs. Bob Fenner>

Wicking EDPM liner      5/15/14
Aloha Bob (or whoever reads this),
<Howsit Tor?>
I have an above ground fountain that we put in as the centerpiece of a garden of raised beds. Construction is 24" high, 9' diameter ring of vertical Ipe 1x6 held with three hurricane strap bands. Within that is an EDPM liner with concrete bottom on top of liner. It's been up for a while and it looks as elegant as we hoped.
I went around and pleated the liner at each joint in the Ipe (an elegant way to deal with the four foot larger circle of liner than pond diameter), but we are having trouble with small rivulets coming up an inch or more, and working through the pleats to come down outside the fountain.
<Ah yes... sp3 hybridized... water... capillating if you will>
The fountain has been going down 1-2"/week, but we've just been using plumbing strap around the edge to hold the liner in place, and it seems to make the rivulets more numerous, if not slightly bigger as well.
I'm thinking towards sealing the pleats down with something, but it would be really nice to have something that could be injected into the wet pleat, rather than having to take the band off to dry out the pleats. Any suggestions as to the best method of sealing this?
<Mmm; I would take the water out, dry thoroughly. It's hard enough to get anything to stick to EPDM...>
Thank you,
Tor
<Do write back re your experience/s please. Bob Fenner>
Re: Wicking EDPM liner    5/16/14
Aloha Bob,
Thanks for your reply.
<Welcome Tor>
> I'm thinking towards sealing the pleats down with something, but it
> would be really nice to have something that could be injected into
> the wet pleat, rather than having to take the band off to dry out
> the pleats. Any suggestions as to the best method of sealing this?
> <Mmm; I would take the water out, dry thoroughly. It's hard enough
> to get anything to stick to EPDM...>
I kind of thought as much. Do you think there is a silicone or other caulk that would work, or would I be better off to open the pleat, put a piece of seam tape over the entire open width, and close the tape back on itself?
<Yes; the tape is the very best possibility... As stated previously, little sticks/welds to EPDM directly>
It is at least outside, but even with Ipe not having water dripping down is a good thing.
Thanks,
Tor
<Welcome. Bob Fenner>

Expanding a concrete pond, adding a filter       7/7/13
Hello, I have a concrete pond that I had built in my backyard in 2004. It's about 15 ft. long and about 2.5 ft wide with a 6 ft. tall waterfall. The depth of the water ranges from about 12 in. at the lowest point
<Too shallow>
 to about 30 in. at the deepest (where the pump is). For some reason when I had it built, I either didn't ask for or the builder didn't install a filter so I'm doing the water changes and filtering myself (a very time-consuming job as you can imagine).
<Ah yes; I'd retrofit/add a filtration system for sure>
 I currently have one Koi that's about 8 in. long (bless his/her heart what a trooper). There's also another Koi that is about 4.5 in. long. Both of them are doing great.  I had two smaller Koi that were only 3 in. or so and I haven't seen one of them in a couple of days. The other one I glimpsed yesterday. There is a pond professional who is going to work on the pond to find and seal a slow leak and also to install an outside filter.
<Ah good>
 My question is whether it would be possible to built up the sides so I can add another 6-8 inches of water.
<Yes... I'd add a liner to all... Read here: http://www.wetwebmedia.com/PondSubWebIndex/conclnrconstpd.htm
and the linked files above>
The pond guy wouldn't even consider it.
<Mmm; I'd look around for other help>
He doesn't like concrete ponds and only uses liners.
<Am a huge fan of liners as well; for underlayments>
 The only reason he's helping me out with the leak is because we're both in a Koi pond association where we live. That's in far West Texas, by the way, which I understand is better for concrete ponds because we don't get extreme freezes. What is your advice?  -- Bobbie
<To read on WWM re such work; cast your net further help-wise. Bob Fenner>

Concrete pond retrofit 6/24/10
I have thoroughly enjoyed reading and searching your fine website for many hours. Unfortunately, I've been unable to find answers related to this retrofit question.
<Go ahead>
My 1,000 gallon pond is 15 years old, concrete with block walls all below grade level. It's heavily reinforced with rebar and the blocks were filled with concrete when constructed.
<All cells I'll take it>
I have no noticeable leaks despite my failure to employ a liner. I'm planning a retrofit to fix plumbing and filtration design sins. The plan call for addition of a bottom "retro" drain going through 3" PVC or ABS, all gravity fed to a pre-filter before pump.
However, this will require piercing concrete wall (by excavating from outside of pond) to add a "thru-hull" pipe. I'd appreciate suggestions of materials and procedures to add this pipe without opening a can of leaky worms in my presently water-tight pond. Can it be done? Regards, Martin
<Well... there are expansive adjuncts to fill in about such retrofitted plumbing. My fave manufacturer is Thoro products... I suggest you read over their offerings: http://www.thoroproducts.com/
Bob Fenner>
Re: Concrete pond retrofit 6/24/10
Bob, You're the greatest. I'm very impressed by the offerings from Thoro.
<Me too. I have used their products hundreds of times... they are "the real thing">
Many thanks for this info as I will no proceed with more confidence--after I call them and confirm product applicability. Again--thanks!!!!
Regards, Martin
<Welcome. Do ask whomever you speak w/ re their "batch plant" locations near you, dealers who carry more/most of their product line. BobF>

Re: Sea shells in Koi Pond, now leaking... 5/13/10
Gezzzzz, Bob... you make an Italian, French, Irish gal look foolish.
Didn't think you'd notice that the Italian spelling of Ciao wasn't on the money.
You're good... but with that last name, didn't think it would make a difference!!!!
<No biggee Barbi>
Incidentally, my shells will have to be put on the back burner right now... I've got bigger fish to fry (definitely pardon the pun) 'cause I'm a true vegan. Just had the upper waterfall and small ponds redone last weekend yesterday morning I discovered an overnight 4-1/2" water loss. Can you recommend anyone in my area (44406, 44512 and 44515)
<Mmm, where is this? Can likely be looked up on the Net... but I'll default to suggesting you call other folks in the area who have hired people about you for their input... Via Craig's List perhaps>
who is reputable that does ponds? The only company I know has only a one-man crew and there is a waiting list, of course, and he doesn't constitute this an emergency. Thank God for low temps and wind, however. Have two aerators going and an air stone, but every time I start the pump... out it goes. Just frustrating... as I'm still waiting to put my Microbelift in and test.
<Oh! Saw these folks today at the tradeshow here in Germany>
That's the reason we had everything redone... water loss. If you have anyone in mind, would appreciate a referral. Thanks, Bob... and Ciao ciao, bambino!!!!
<Gutnacht mein fraulein. B>

Re: Sea shells in Koi Pond 5/14/10
Bob... you're in Germany? How cool is that??? I was asked to create Biscotti flavor for a friend's wedding (VERY Italian groom and VERY German bride) but when told they needed a minimum of 300 pieces... I opted for dessert at their Rehearsal Dinner instead. One of my more memorable creations was for the guys at the Cleveland Zoo, Aquatics Division, who walked me through my first spawning witness. Brutal, to say the least. I think now I would definitely opt to be a male Koi!!!!! Anyway, got to go... "pond guy" is coming in a few minutes. Let's see what this adventure brings!! Thanks for the suggestion but tend to shy away from Craig's list... Twitter and Facebook... too busy to sit here for more than 20 minutes!!!
<I see>
Again, Bob... it's been a pleasure kibitzing... and... I absolutely love the Microbelift line. Use their PL for good bacteria, usually a little Sludge Digester at spring opening (which have been unable to do -- yet) and a little Ultra Clear maybe once a month. That's it!!! Been very lucky... but my finny guys have a good mom!!! Ciao, Barbi
<Wish you were here. BobF>

Re: Sea shells in Koi Pond... leak 5/18/10
Not so fast, there, guy... pond NOT REPAIRED yet!!! A borrowed pump is in upper small pond in lieu of installed pump being on to "see if there is a leak in the big pond".
<Barbi... have the "repair people" pressure test the plumbing/lines... easy to do... And add dyes to the basins and test the "water outside" for at least the general source of water loss...>
I know there is not!!!!!!!! It lies either in the waterfall he rebuilt last week...
<Mmm, these can be real sources of trouble... Have you read my olde piece on WWM re waterfall construction? Really need a continuous liner... laid in over a "structural trough">
or the lip flowing into the pond which he really shorted... or the huge, sewer-like pipe from skimmer to bottom of falls box. Yikes......can't stand it!!! You're a good listener, Bob... it's raining... and I just did my windows yesterday. I just love doing futile things!!!!!!! Ugh......yuk......and a few other disgusting remarks not recommended saying on the internet!!!!!!! Barbi
<Steady on Barb... BobF>

Re: Sea shells in Koi Pond, fall repair, reading... 5/19/10
Hey, Bob... will pass on your suggestions to my pond guy... and no, have not read your piece on waterfall construction.
<... Please do: http://wetwebmedia.com/PondSubWebIndex/h2ofallconstr.htm
and the linked files above. B>
I really have my [usually right] gut feeling that my problems lies within the plumbing in the skimmer box to
the falls box or the connection to the falls box. Either/or... dollars being spent and no return other than complete frustration. Not to mention my snow/ice/rain damage in my bay window and insurance adjusters not able to come to assess the damage till Friday. Good thing I don't drink... though perhaps I should start!!!!!! Barbi

Re: Sea shells in Koi Pond 5/20/10
Thanks, Bob... took a break from "give constructive criticism" to my painters... i.e., please don't drip on the carpet... I don't care if it is Latex... there are six drips in this corner... my wall paper didn't have white edges before you started... why does my vintage brass door knob have a white shadow around it... I'm literally ready to tear out my hair!!!!
<Don't do it... step outside yourself... Are you given/partial to the written/printed word? Try "The Book" by Alan Watts... you're a candidate>
Read your short and sweet (like me) article on the falls construction;
<And your writings, musings urged me to spend a few hours ayer splitting up the three Pond Repair FAQs files into more specific sub-categories... including H2O falls>
unfortunately it is too late as it is already done and some of those large boulders are in excess of 1,000 lbs.
<Mmm, actually... a liner can/may be laid in over the area where the water transits, overlaying the pond lip... mortared and more in...>
(Took two men and two pinch bars just to move 'em.) I know... far too large, but that's what was done initially
when I was in my "damn the expense mode". I've since come to my senses!!!!!!!
<What lacking is there in us that our senses don't register the many worlds around us?>
Anyway, thanks for all your help Robert... really appreciate it. Barbi
PS
Will let you know when I am again sane!!!!!!!!!!!
<Ok. B>

Leaking pond made of concrete sections 4/29/10
Our 9' diameter pond was constructed of 6 concrete sidewall sections, all of which are cemented together and on top of a concrete deck (base). To stop leakage at the concrete-grouted seams where the sections abut each other and between the sections and the concrete base, I have successfully used Marine GOOP, a clear and goopy sealer
applied from a tube and smeared over the leaking surfaces.
<Am familiar... is "amazing">
After 10 years of mostly leak free operation, the pond is now leaking rapidly and re-application of GOOP has not solved the problem. I have removed the newly applied GOOP using acetone but have not yet applied it a second time. The seams are flush with the side sections and can't easily be caulked. The side sections are made to look old and are impregnated with a color stain. Using a liner or applying an overall coating is not acceptable. Do you have any other suggestions for sealing the seams?
<Mmm... there may be a elastomeric product that will work here... The seams will have to be meticulously clean and dry... I'll plug my fave line: Thoro: http://www.thoroproducts.com/
and read here re use:
http://wetwebmedia.com/PondSubWebIndex/thorselfaqs.htm
and the linked files above. Bob Fenner>
Re: Leaking pond made of concrete sections
Thanks for the information.
<Welcome. BobF, who's been there, done this...>

water feature... repair of pre-cast ftn. -- 12/15/09
hi, I
<... English?>
have a concrete water feature that my wife knocked over last night,
<!? With a car?>
the water reservoir part of the feature was broken into 4 parts 3parts make up a third of it the other part is whole the total size is 3ft across, my question is, is there an adhesive strong enough to bond it back together,
remembering it is also 5inches deep and can hold a decent amount of water, thanks
<Oh! There are a few types of epoxies, even (if the base is stable) thin-set mortars w/ adhesives added (see your local specialty masonry, stucco... supplier... Bring a piece of the ftn. for color matching) that will put "Humpty Dumpty" (and his fountain), back together again here.
Cheers, Bob Fenner>

Leaking concrete pond 9/30/09
I just found your website and have a question. We have a very large pond that originally was a swimming pool - concrete and rebar. It has numerous cracks now and only holds water to a low level. We're right on the water table - living on a bayou in Florida. A pool place suggested rather than empty it and reconcrete, etc at great expense, we should create algae which should seal the cracks. He advised us to add nitrogen and phosphate and fill the pond in order to grow algae and thereby plug up the leaks.
<Mmm, no... Too likely to have ongoing REAL problems with excess algae... insect vectors even as a consequence of so much algal proliferation>
Is this a good solution to the problem?
<Not IMO/E>
Will these chemicals harm my water lilies, fish and other plants?
<Can, yes>
It sounds good to me but I'm hesitant without some feedback. Any info you can provide will be GREATLY appreciated. Thanks in advance. Kathy Gresko in Florida.
<The least expensive, most sure repair/solution is to place an adequate liner over the existing structure/basin. Please read here re:
http://wetwebmedia.com/PondSubWebIndex/conclnrconstpd.htm
and here:
http://wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm
and the linked files above. Bob Fenner>

Repairing & refilling Koi pond 8/20/09
Hello Crew!
<Mark>
I desperately need some help, suggestions & answers re: repairing & re-installing a Koi pond. After a frustrating search for the source of the leak(s), we have faced the conclusion that the pond will need to be re-lined rather than repaired. Here are the basic facts:
. in-ground, rubber liner, about 1600 - 1800 gal, about 7 y/o.
. using an exterior biofilter from Tetra which has never been back flushed; pump to biofilter more than adequate for turnover of water, about 2000gph
. water quality is clear, algae-free, water chemistry is good (ph, nitrate, 02 etc.)
. currently stocked w/5 Koi (9" - 16") + 3 baby Koi <4", + 1 comet (6").
All are healthy, vigorous, beautiful!
. planted w/Anacharis, water lettuce, water hyacinth.
This pond is also contiguous to a "bog" area, rubber-lined & separated from main pond by rocks, planted w/thriving iris, pickerel weed, arrowhead etc.
The main pond has been losing about 6" water daily & have been re-filling w/garden hose every 48hrs or so.
Currently in the NYC area, the weather is very hot, 90+ w/no real end in sight to the heat wave. It's also been raining often & heavily, so between the heat & the rain, it's been hard to be able to get at the pond. We've tried unsuccessfully to identify the leaks, so are now planning to dismantle the pond, re-line & return the fish, plants etc.
The dog work of removal of rocks, plants etc. will be daunting, but we are willing to do this ourselves. The tricky questions are about how to "warehouse" the fish & how to re-store quality to the pond water.
<Big "wading pool">
Due to budgetary concerns, we are definitely going to have to improvise how to hold the fish & do all the work ourselves.
1. How to store the fish safely? In 55gal plastic garbage barrels?
<Nah>
Small (450g) wading pool?
<Much better>
Water would come from pond, itself.
2. What kind of aeration system will we need to keep oxygen levels in water? What kinds of pumps, airstones etc.?
<Best to use what you have currently...>
3. How to keep water temp low enough? Shade w/patio umbrella? Floating plants? Bags of ice?
<All the above>
4. How long could the fish survive in this environment?
<Easily a week or two>
5. What are the best ways to re-store pond water quality?
<Return the stored water and filter sans cleaning>
How long would it take before it's safe to return fish to their pond?
<... immediately. Add some water conditioner for the remaining 1k or so gallons you're adding new>>
There'll be some microbial benefit from returning water that the fish have been kept in, also from plants, running the biofilter & pumps. What about adding commercially available de-chlorinators, microbe-lift chemicals? Suggestions for brand names?
<Kordon/Novaqua or API equivalent... Microbe-Lift's products are very good>
6. Am I crazy to even think about trying this myself?
<Not crazy at all. Just need some strong help to lay down/over the new liner (Oh, and do take care when stepping inside the current one... treacherously slippery>
The pond, the fish, the plants, the water have been a labor of love & a are great source of pleasure. The pond was made by myself & another friend, ourselves. We made all the classic beginning mistakes, but the pond has been thriving & flourishing. I bought the fish when they were small at a local aquarium shop & they have grown into beautiful beautiful creatures.
I would hate to lose any of them.
<Should do fine... just take your time>
After an internet search, I was very happy to have found your site, it's the most helpful & knowledgeable of any I've read. I hope to hear from you soon.
Thank you for your time & consideration.
-- Mark Harada --
<Glad to help. Bob Fenner>
Re: repairing & refilling Koi pond 8/20/09
Wow, thank you so much for answering so quickly & in such detail!
Feeling much better about the whole thing, now. My main fear was that we'd end up poaching the fish!
<Not to worry>
The only thing I'm not clear about is your suggestion to use the same pump that we use for the pond for the kids' wading pool. Won't it be too strong for a much smaller volume of water?
Thanks, again,
-- Mark --
<Will not be too strong, I assure you. BobF>

slow pond leak 5/4/09
A few years back I ran across a product (didn't need it then but wish I would have paid closer attention because I do need it now) that seals leaks in a concrete pond......I have a concrete pond leak the leak is on the top edge probably around 1 of the 2 leaf skimmers, I have tried sealing it, to no avail. I cannot think of the name of this product you pour on the water...it floats...going to the leak, which then it adheres to the spot and seals itself up. I cannot think of the name of this product...are you familiar with it? Thank You Judy
<There is, and the name escapes me as well... I'd call a few of the large/r pool/spa supply companies re... or peruse WWM here:
http://wetwebmedia.com/PondSubWebIndex/thorselfaqs.htm
and the linked files above. Likely Thoro's "Water Plug" product would work here if you can determine the approximate area of the actual leaking. The mixed in water product/material in question can't be used w/ biota present... Bob Fenner>

Koi pond, leak... 1/10/09 Hi, <Dawn> Your site has been of great help during the construction of our first pond. I have run into a problem that is not really addressed any where so your help would be wonderful.. We have built a Koi pond for a client in the Virgin Islands. It is about 900 gallons and is concrete, the seal is Thoroseal with a grey green dye. The pond has an Island in the middle on which sits a large rock 3'x4'x2'. A pipe is run through the rock <Mmm, no liner I take it... and this pipe somehow has water about it... either from the fall or penetrating the basin?> to the top and then through a copper bowl. A slow fountain pump fills the bowl with water which then spills over the rim of the bowl and down the sides of the rock. It was decided to raise the water level about two inches above the joint between the rock and the concrete pond. <Ohhh, likely leaking> We have begun experiencing a leak which stops as that joint is reached. Since the leak is about 1/2" in a 24 hour period and since the owner would really like the water level to stay the two inches up the rock we are wondering about sealing the rock in two areas. <Mmmm> 1.) To solve any leaking at the joint which we suspect is the major problem (due to normal expansion and contraction of the rock:) put a two inch silicone bead at the joint (however I see on your site that silicone may not seal a joint between rock and concrete) or put a two inch collar of epoxy grout which should seal to both the rock and cement with no problems. Finally the last choice would be to build a cement and ThoroSealed collar over the joint extending just above the desired water level <Mmm, none of these is likely to be effective... Thoro has other products> And if we fix the first problem but still have water loss then we would proceed to fix #2. 2.) To solve the problem of both excessive evaporation from the fountain water hitting the rock and to solve the porosity of the rock from soaking up water from the fountain we thought that sealing the rock with a water based stone tile sealer like Aqua Mix Sealer's Choice Gold might work. <Not likely at all unfortunately> It is clear and there is no shine and it is good for exterior use. Of course we would first try it on a small area of the rock before leaping into this fix. If you have any suggestions about either of the two problems or the products that we have come up with I would be most grateful for your help. Thanks, Dawn <Your "for sure" options are few... rebuilding all over a water-proof liner. Please read here: http://wetwebmedia.com/PondSubWebIndex/thorselfaqs.htm Bob Fenner>

Re Leaky Koi Pond 01/13/09 This is a follow-up to mashngo's e-mail about my pond. We could not use a liner as we started with an 8ft x 4ft x 4ft bluebit granite rock at the pond's center. <Been t/here> We dug a doughnut around it to 4 ft and lined the perimeter with reinforced block/cement over painted with Thorough Seal. <As I understood, understand> We appear to have a slow leak at or around the rock/block border. <Very common> See my drawing. <Very nice illustration> Any ideas for sealing the rock itself or the interface would be very much appreciated. <Mmm, the "next level" approach I might take here (other than abandoning the current structure, emplacing a liner over all... adhering this to the border/rock, above water level) is to use another fine Thoro product called "Water Plug"... needs to be mixed up, used in small patches (cures quickly)... practice, measuring for added color (if being used)... to match all the way around... the area needs to be thoroughly clean... no biological film present> I don't want to change the "look" of the rock with the sealer. Does Thorough Seal absorb water? <Mmm, minimally> Thanks, Jack <Welcome Jack... I do hope I'm being a bit more clear, complete here. Do contact me if not. Bob Fenner>

Re: Leaky Koi Pond Hi! Bob, <Jack> And thanks for the prompt reply. Your message is very clear but I don't think we have the space to line the existing structure and hide the rock / liner interface with rocks or a ledge etc. So for now at least we'll try to plug the leak. <The Water Plug product is a worthy try> But thanks. I did not mention that there is a waterfall spilling down the rock and there may be some water loss into the rock by absorption or via fissures. Is there a clear spray or brushable sealer out there that will not significantly change the look of the rock but seal it? <There is not... or to be more fair... All of the ones I have had first, and reliable second/other hand experience with have not proven efficacious... I might try dabbing the Water Plug in the crevices twixt the rocks in the fall> Fish/plant safe of course. The reason that we are all so paranoid about water out here is that the only water available infrequently falls out of the sky. Or you can buy it for about $1 per gallon. <These materials have neither "body" nor "stretchability"... and surprising to many folks... rocks do "move"... expand/contract with temp., moisture/drying...> Thanks again. Jack. <Welcome. BobF> Re: Leaky Koi Pond, fixed, now high Alk. from Thoroseal 2/13/09 Thank you for your help earlier. I now have a leak-proof pond. The ThoroSeal finish was really helpful. <Thoro does have some very useful products for sure> I am now having problems controlling the pH which, uncontrolled, will drift up to >8.5 in 48 hours. <No worries... allow to "soak" for a few days, drain, perhaps do a dilute acid-wash (see WWM re), and re-fill> The whole pond is ThoroSealed and I use only rain water for filling. The rainwater's pH is 7.5. I have nothing else in the pond likely to affect pH I noted that on the MSDS for ThoroSeal it says that it is alkaline, but does not say how much. <Yes... tis the alkalinity in this product that has bolstered the pH here> Does the alkalinity leech out and finally go away. <Yes> Is there anything else I can do other than keep adding acid? <Mmm, time going by...> Thanks. Jack <Please read here: http://www.wetwebmedia.com/PondSubWebIndex/acidblchpds.htm and the linked FAQs files above. Bob Fenner>

Pond Dried Up... Oh no! Holding tank set up, op. 10/23/08 Hi, I'm contacting you for this reason: my pond dried up. I had no clue it did until I returned home from college one evening and my mom asked me to help her collect the fish. They were very easy to catch, if that gives you a hint of how shallow the water was. My mom knew of my love of fish and asked me if she could use my 30gal tank to hold a small portion of the fish chosen (possibly a max of 30). They're all small specimens, and only a max of 10 fish are at 1". I'm disappointed in my mom because she doesn't even know the type of fish she bought. I don't know either because I'm more of a saltwater enthusiast. My mom thinks they're bass and minos so I'll just go with that. <Bass eat minnows, so mixing these fish together isn't exactly recommended.> I have two power sweeps (yes I know they will get stuck sooner or later) that I'm willing to donate to my mom that get 270gph and I was thinking of getting an Emperor Bio-Wheel (400gph) so that I can use filter media (e.g. carbon to make the water clearer). <Carbon doesn't make water clearer. Carbon removes dissolved organic chemicals, and in freshwater tanks is almost always redundant provided you perform regular water changes. Concentrate on mechanical media (which removes silt) and biological media (which removes ammonia). Unless there's some overwhelming reason to get a hang-on-the-back filter, I don't recommend you choose one; standard external canister filters are better value and more flexible, and don't force you to use proprietary filter modules. Sponge filters are also very useful when maintaining small fish for short periods.> I also will be using reverse-osmosis water, and all the other correct electrical devices (e.g. heater). <Why are you using RO water? Remember, pure RO water is lethal to freshwater fish. If in doubt, stick with tap water treated with dechlorinator. This should be reasonably close to the water these fish were inhabiting, assuming your water supply gets the water locally. Do not use water from a domestic water softener.> I'm going to purchase an array of fish food so that the fish will have a varied diet. <Minnows and bass obviously eat different things, but wet frozen bloodworms and mosquito larvae should work well for both, at least while the Bass are small.> Water changes weekly (keep pH at 7... it's a safe number for freshwater I'm guessing). <Preferred pH actually depends on the species in question, but pH 7 should be fine for these species.> I wanted to know if allowing the water to cycle 24hrs would be good enough to then introduce the fish? <You can't "cycle" a tank in a system without ammonia. By definition, cycling is how ammonia-consuming bacteria get established. There are products on the market (like Tetra SafeStart) that supposedly "instantly" cycle a tank when used correctly. At least some of these (like Hagen Cycle) are of questionable success in this regard, but better than nothing. In any case, your best bet is to grab some live biological media from another filter on an established tank and put into your chosen filter. Do read here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm > We're keeping them in buckets for now outside (very hardy to those conditions; very different from saltwater :D). And I wanted to know if I could keep the tank with a bare-bottom? <Fish aren't wild about bright colours underneath them, so plain glass or white plastic don't go down well, and the fish get scared easily.> I know the algae will help within the substrate at the bottom of the tank but we're only doing this for the winter so that when our pond gets back to its regular size the fish will be reintroduced into their natural habitat. <I'd scatter at least a bit of smooth silica sand or gravel. Just enough to cover the glass.> Thanks for the help, Jeff <Cheers, Neale.>

"Water Loss", pond 6/10/08 Hello, I got a question in regards to my 12' X 14' X 4' (deep) Koi pond with a 4' in length of stream (about 16" wide).&I live in Southern California, and is it unusual to lose about an inch of water over 24 hours period given my set up/weather here? <Mmm, such amounts can be due to "simple" evaporation... given low humidity, high/er temperature, wind...> Please let me know. I've looked around the pond trying to detect any possible leak and I've yet to see any evidence of that. <There are companies who specialize in detecting such leaks... If this amount of water loss is prohibitive (we live in San Diego... so know the cost of water) or a concern in terms of not knowing where it's getting off to... perhaps damaging someone's property... I would look in the Yellow Pages (see Swimming Pools... repairs), and call a co. re. Bob Fenner>

Rectorseal Epoxy in Ponds/Aquariums -- 01/31/08 Bob, <<EricR here tonight>> Do you happen to know if Rectorseal EP-200 Epoxy Putty is safe for use in ponds etc? <<It is>> I need to seal an outlet from a home-made filter and this is all I could find locally. <<I have used Rectorseal EP-400 for years in my reef tank with no deleterious effect. I believe the difference between the -200 and -400 designations is the size of the container (2oz vs. 4oz)>> Cheers for any help! Tom <<Happy to assist. Eric Russell>>

Reconstructing old concrete ponds 12/16/07 Hi, Bob and company, <Sarita> The project in question is an 80 year old meditation garden with several small (10' - 20' widths) ponds and a stream bed, all with cracked concrete. A recent attempt was made at fixing them by simply covering the old concrete with pond liner, but not the good EPDM rubber liner ~ rather the much stiffer, wrinkle ridden polyethylene liner. <Neither attractive nor lasting> This has resulted in an aesthetic challenge, among other problems. Tons of head size and slightly larger stones have been piled along the edges to cover the liner with questionable results. <... and a maintenance nightmare> My redesign involves removing the small stones and bringing in big boulders (that exist on the property ~ they are fortunate to have an amazing supply of natural boulders and stone!) . In the process, I will need to bust the concrete out at least around the edges of the ponds and stream bed in order to accommodate the boulders in a naturalistic way (digging them partly into the stream banks). <Mmm, yes...> I would like to save the owners some money in redoing the work. Where possible, it would be economical to reuse the lining which they already spent a good deal on. <Not likely... they and you would be better off starting new... removing the existing, breaking the edge and making "islands" where you intend to mount the new large rock, laying in a new liner with mesh, shotcreting all, placing the boulders, mortaring in around these... with the liner higher than water level behind... all within the basin...> I have some questions: I will be mortaring my stonework and am considering using mortar to cover any exposed liner (with a Quikrete colorant to simulate the stone/local soil color) and will use an acrylic strengthener. Will that be enough over the poly lining? What thickness do you recommend? <20 mil plus> Should I paint the liner with a cement glue first? <No... no advantage> Mold aviary wire over the liner surface? <Yes... or stucco, chicken... wire> How about adding fiber mesh to the mix? <If there's money in the budget, this won't hurt... I'd rather spend the money on better and more (plasticized) cement> This is at an elevation that typically has +25° lowest winter temps, 100+ summer highs. I believe soil heaving is mitigated by the many tree roots of the surrounding forest, but I would like any advice you have on mortaring for cold weather, and mortaring over liner, especially as I intend (though not by preference!) to re-use the poly liner for the water containment. <Mmm... is the feature to be drained, water-less during the freezing weather? If not, I would not be concerned especially... Again, I would plan on replacing the existing liner... it is VERY likely perforated, will suffer further piercings with the new work... I would remove it rather than lay over the new one... Butyl would be best...> Thanks so much for your website! Contribution forthcoming! Sarita <Yay! Be chatting, Bob Fenner>

Re-install Large Pond In Clay Soil, Pond Near House Re Installed After Collapse 11/15/07 Dear Crew. Put in 4' deep x 8' wide x 33' long Koi pond about 3 years ago. < Wow, that is a really big pond.> Concrete block mortared together for side walls. In bottom we put 2" sand, then underlayment of carpet backing, then EDPM vinyl liner. We included a large biological waterfall (using a 150 gallon rubber water tank filled with filtering materials). The pond lays 4' from the house and stretches along the length of the front sideway between the house and the sidewalk. The soil here is clay and develops very deep wide crevices during the heat of summer. < A typical expansive clay.> About a year and half ago we drained the pond because our house foundation fell. We had a contractor put concrete piers along the perimeter to re-level. We don't know if the pond had anything to do with it, but don't believe it did, although we continually had quite a bit of water loss that we feel was the waterfall. <The house fell for a reason. The piers transfer the load of the foundation from your house down past any influence from the pond. Hopefully the soil there is much stiffer.> In the meantime our two gorgeous Koi have been living in 150 gallon tank, and we want to go ahead and re-install the pond, but want to take extra precautions against any possible leaks as it is so close to the house. Do we need to do anything extra than your suggestions of liner, then concrete, etc.? My plan is to keep the old liner in (although not trustworthy as re-modeling materials during structure tear down were thrown into it), go ahead and put a new liner in and proceed from there. Also, we have decided to bring the pond up to a 2' depth and need advice as to what material would be best to do this......just dirt or what about pea gravel......or sand?? This would go over the old liner, and then we would continue per your site instructions..... Sorry to be so lengthy but would appreciate any thoughts before we do this. Thanks Darla McLeroy <Any material that you use to bring up the pond bottom needs to be compacted to prevent differential settlement. Use whatever is the most cost effective and densify the material in 8" lifts using a mechanical hand whacker up to the grade you desire. The last lift or top material needs to be a material that is recommended by the manufacturer of the liner. If you use a pea gravel as fill then a sand used on top will just fall through. If you use soil it needs to be free of any sharp objects like stick and stones. Pea gravel is almost self compacting but holds lots of water between the pore spaces.-Chuck>

Leaking underneath a cement dam.. 9/6/07 I have a cement dam about 40 ft long and 8ft high...3' wide...a beautiful acre pond behind fed by a small stream...this summer the stream dried up and all the water leaked out gradually from underneath the cement dam somewhere....how should I go about the repair ..please advise....Mike <Mmm, w/o knowing more, I am inclined to encourage you to have a soils engineer out to test the "overburden" of the material on the bottom, look about for areas of leaking soil-wise... and possibly a structural engineer to survey the extant dam... may need substantial re-doing... Have you taken a look/see where this volume of water would likely go given a catastrophic dam failure? Bob Fenner>
Re: leaking underneath a cement dam.. 9/7/07 Hi Bob...its not that big a deal as you seem it is...the spillway of the dam leads down into a major river... <Ah, good... a relief> I believe the Dam is leaking underneath in one place....Will the treatment of sodium Bentonite probably solve my problem ?? <Is a good, semi-inexpensive worthwhile try IMO/E. Do dish it in well Bob Fenner>

Faux rock repair around my pool 9/2/07 I live in Las Vegas. The faux rock waterfall that is part of my swimming pool has started to crack in various places. The calcium from the salt system leaches into the cracks. The pool is 7 years old .The rocks are a typical wire mesh/rebar/stamped & stained concrete variety. The cracks themselves are no bigger than 3/32" wide, but some are as long as a foot or two. Researching the net doesn't really address a specific technique....could you be so kind as to advise me on a DIY??? respectfully, Michael Best <Mmm, yes... there is a Thoro Product called Water Plug that is a very fast-setting mortar that actually expands when it cures (most cementatious materials shrink)... I would get this, and an oxide to color it (take a sample of your rock to a stucco company and they'll match it for you), mix the two together dry... in small batches (the amount you can use in under five minutes). Apply with a sharp trowel, wipe with a yellow sponge that is damp... Voila! Bob Fenner>

Underwater Paint Repair 8/5/07 We recently purchased a house with a pond which is +/- 1200 gal and about 30" deep. It is concrete lined and the liner was originally painted white. <... really? What sort of liner material is this?> The rebar was apparently close to the surface and is now rusting through in some areas. <Too typical... the shell wasn't waterproofed itself...> We are concerned that his could lead to leaks and/or failure. <You are wise here> Is there some non toxic (we have several gold fish in the pond), underwater paint I can use to contain the rust and re-coat the concrete. <Mmm, yes... a few things... depending on how involved you want to get (money and time-wise)...> We have drained it once and really don't want to do it again. We appreciate any thoughts. Thanks, Pete <Please read here: http://wetwebmedia.com/PondSubWebIndex/thoroselart.htm and the linked files above. Bob Fenner>

Problem with my large <earthen> fish pond 6/13/07 Dear sir I have a large commercial fish pond, approximately 1 acre of sandy soil. The depth is 30 feet. My problem is that the water level goes down drastically during the winter time. My pond is situated on an agricultural land. The leakage happens mostly during irrigation period. I live in Bangladesh. How do I stop the water from seeping / receding out? Please help! Regards Tanvir <Mmm, likely there is a local clay product that can be dished in (while this basin is emptied of water) that will render an impermeable layer to the bottom. Do check with your agricultural extension agent (or such) there re "Bentonite" clays. Bob Fenner> Re: problem with my large fish pond -- 06/14/07 Thanks a million Bob Fenner, That was a great help <Ah, good> Keep up the good work at Wet Web Media Tanvir <Am trying my friend. BobF>

Fiberglass pond repair -- 06/07/07 If you resurface a pond with fiberglass is it safe to put fish in it, or will the fiberglass kill the fish thank you Frances <Needs to be cured... but can be done... Not the best material in almost all cases... unless the original construct was/is fiberglass and resin... Please read here: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm Scroll down to the tray on "Repair". Bob Fenner>

Need to seal pool 5/10/07 Pool 25 meters long - 15 meters wide - up to 7 meters deep if we could fill it. We need to find a way to seal our concrete and rock swimming pool/pond/lake. This pool was very carefully constructed out of rocks <... that penetrate the basin...> and concrete and we expected it to leak BUT we did not expect that our 20+ gallons per minute pump would not even be able to half fill it before the pump could not keep up with the leaks. <And wonder what the disposition of the missing water is...> We have since emptied it and meticulously grouted between all the rocks <... not easily done...> with a 50/50 fine sand cement mix which helped but and we got it a little fuller but still not good enough for the pump to stay ahead of the leaks. We don't want to cover the rocks if we can avoid it and we are looking for a product that will penetrate and make it considerably more watertight. <There are hydraulic cementaceous products (that expand rather than contract when curing/cured)...> The pool is in Honduras, which is sub tropical and we are therefore not concerned about the effects of temperature changes during the year. It is always shorts and t-shirt weather here. 12 hour days all year round and warm to hot ambient temperature. We have a permanent water supply from our shallow well right beside the pool and only need to pump a 24 foot head to fill the pool completely (if we slow down the leaks sufficiently). Any suggestions, ideas, help and/or assistance will be most appreciated. <Ask about re companies in the area... perhaps ones that work on engineering, building the roads, large concrete structures like buildings... e.g. "Water Plug" by Thoro Products would work here... but expensive...> Our main project here is a school for poor children and this pool has been built for the specific purpose of also teaching the children to swim. We can also arrange tax deductions for any products or portion of products that you might like to donate if you are so inclined. Looking forward to hearing from you Regards Ben Udy project director Cofradia's Bilingual School <www.cofradiaschool.com> <Bob Fenner>

Sealing EPDM liner to cement... possible, but messy 2/19/07 Hi, Bob <Eric> I am redirecting an existing waterfall through a narrow gap between two very large hard to move boulders into a new creek, so I need to link between two sections of EPDM with concrete between them (concrete to serve as "pond liner" within the narrow 3"-4" gap between boulders and extend several inches out in both directions. I do not want liner to be visible in gap between boulders. Can I bond the liner to the smooth cement with asphalt emulsion UNDER the water level? <Mmm... possibly... a real mess though... wear your absolutely worst clothes... very long, up to the elbow and beyond... "ladies" dishwashing gloves or similar for chemical handling...> If not, what's the best adhesive? <This really is (amongst what is widely available) the best material... there are a few formulations... You want the very "viscous" material... likely labeled for roof patching...> Or alternatively, if I were able to dress the EPDM thru the crack between the boulders, how can I seal it to the rock BELOW the water line? <A VERY good idea to do this at the "low water level" time of the year... BEST by far to divert or dam the water for a day...> Asphalt emulsion , construction adhesive calk, RTV calk, polyester resin??? <Only the first will work IMO> If I go the cement route, is there risk the bond between cement liner and the boulders will crack from settling or whatever creating a leak? <Always, yes... best to fit this with large, well-shaped rock... and fill the gap (best to actually make a "form" first, and build to fit closely OUTSIDE the system), with a very fast settling cementaceous product like Thoro's "Water Plug"...> Perhaps I should cast in a 1/2" gap between the concrete and boulders on each side and calk it with flexible sealant like that used on swimming pool decks? <Bingo! A wise choice> Thanks, Eric <Welcome, Bob Fenner>

Repairing fiberglass waterfall - 12/04/06 I am trying to repair a prefab fiberglass waterfall. There are no cracks in it. It has lost its original coloring as it is nearly 6 years old. <Yes...> We have about 7 fish and I don't want to use anything that will harm them. Do you know if regular colored grout can be used? <Do know, and no, cannot be used> Thanks for any info you could send my way. <A repair can be made if the original fiberglass/resin isn't too badly delaminated, and the area behind the break is supported well enough (not too flexible)... with fiberglass cloth (look for in determinate widths), color/ing if you'd like, laminating/hot-coat resin and hardener, oh and a "throw-away" small brush to apply it. The falls must be dry, clean, and I'd roughen up the surface with a low grit sandpaper of sorts... do wear gloves, long-sleeve shirt and avoid the bits of fiberglass removed... let cure... Bob Fenner> <<Bob, as I read this letter, I thought he was simply trying to restore coloration to an aged fiberglass structure, not repair a structural piece. I was going to try my hand at a reply, but you beat me to it *grin* My suggestion was to be to dry the waterfall surface and try a buffing compound such as 3M Imperial Rubbing Compound to bring back the coloration... Oftentimes oxidation of this sort is simply buildup on the surface of the fiberglass and will buff right out.. I can't tell you how many lake-worn boats I've brought back to a showroom shine with some buffing compound and some elbow grease. Hope this helps! -JustinN>> >Yikes... do see this as you state (now)... Will re-respond... My input remains the same excepting the use of the fiberglass cloth, tape... roughen up the surface, re-coat with colored laminating (not casting) resin and moderate/measured amount of MEK hardener. Thank you Justin. BobF< >>No problem, Bob, its what I appreciate most about the community here: the group think concept. Ideas are better thought out when you have more eyes looking at problems, I only ask for the same if I have any such similar incidents *grin*, Subsequently, while on the subject of refinishing a fiberglass structure as such, what is your opinion of one-part epoxy paints, such as those used for jet skis? These were some of the more readily accessible, easy to use, and cheap types of paint I dealt with in my time in the body work industry, and always gave very nice results. Would you feel them to be adequate for such a situation as described above? -JustinN<< <Mmm, likely so... given very thorough prep... Part of the reason I like the "hot coat" surfboard/use resins... they're much more "sticky", forgiving. Cheers, BobF> Lining a concrete pond 11/18/06 Hello WWM Crew, <Brian> Warm greetings from Sydney Australia where we are just entering summer and enjoying the worst drought in a thousand years (I am not sure how they worked that out as records only go back about 150 years!). <And such even numbers... reminds one of "budget" numbers from simple servants in the U.S.> I am very impressed with your extensive knowledge you share with the Web community and thank you for that. I have a problem I was hoping you could assist with. <Will try> I have converted an old sunken garden into a pond by rendering it and covering the render with a two-part waterproof paint the name of which escapes me. It is about 10 feet by 8 feet and about 3 feet deep. It is a very happy home for seven goldfish and a whole bunch of vegetation. This worked fine for 8 to 10 years but has recently developed a leak. I found what I thought was the leak, scratched it out and filled with a silicon glue (a Selleys product) which seemed to slow the leak down but didn't stop it. I suspect there are roots from my neighbor's pine trees involved. <Very common> I have decided to line the existing concrete pond with a butyl rubber membrane and although I have scoured your excellent website I can't seem to find an answer to my questions. Can you comment on my decision to line the pond? <Is excellent... the roots will not penetrate this material> How should I attach the liner to the concrete? <Best to fashion a "lip" of sorts to hand the membrane in, pinch it to... and cap this with some sort of masonry with thin set mortar> How should I deal with the flaps produced when folding into the corners of the pond? <Try to "fold them in, leaving a bit loose at the top... though all will stretch and largely lay flat on filling> Thanks in advance, Brian Lee <Welcome my friend down under. Bob Fenner> Fixing pond leaks 9/5/06 Hi, I have a small outdoor pond that is old and cement. It has cracks. What filler can I use under water and wet that won't kill the plants or fish? Geralin <... No filler... need to remove all, repair... Please read here: http://www.wetwebmedia.com/PondSubWebIndex/concrepart.htm and the linked files above. Bob Fenner>

Replacing Pond Liner:- What to do with existing fish? 4/18/06 To replace my pond liner I need to remove two 14 Inch Koi and 12 others sized 5 to 8 inches. I understand they will have to be put into a holding tank for about a week. Is there any rule I could use to calculate how much water would be need to keep them alive for this period without any aeration system. If not what can you suggest. Ken Brown <Mmm, the bigger the better... and covered! They can/will jump... out. And don't feed at all, really... but do need circulation, aeration... perhaps just a large "kiddie wading pool" (depth not important if protected from much of the elements (to reduce diurnal changes). Please see here: http://www.wetwebmedia.com/PondSubWebIndex/lnrspdabvh2o.htm and the linked files at top. Bob Fenner>

Convert pool 4/4/06 Hello, <Hi there> We are searching for help concerning my ailing mother's pool. She is in poor health and needs to sell her home which has a neglected underground pool with a compromised water pump. Unfortunately, she lives in Texas while I live in California. Therefore, I have very little time in Texas to complete this project (approximately 3 weeks), and place the house on the market for her. Do you have any ideas that can maximize my time and minimize the costs spent on this project? Any suggestions you may have will be greatly appreciated. With my utmost thanks. <Can be done. Please see here: http://wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm and the linked files above. Bob Fenner> Sincerely, Dawna Kostrzewa

Pond repair - 03/13/2006 Good morning The water feature in our new house which of course is about 20 years old, has not been used for quite some time. Two of the three basins actually have been converted into flower beds. The previous owner had apparently attempted to epoxy seal some areas, they are covered with some type off shiny but brittle materials that doesn't adhere well to their underlying surface. Thoroseal or liner, that is probably the question. Thanks for your input, Michael <Please read here: http://wetwebmedia.com/PondSubWebIndex/concrepart.htm and the files linked above. You will likely want to consider building over the existing basin/s, liner... Bob Fenner>

Sealing edges of rubber liner fix 12/21/05 Hi, I live in NC and purchased 10 beautiful acres with a 50 year old, 1 acre pond on it. It is filled with runoff water. When It rains it fills up nicely , then after a few days the water level drops about 2-3 feet. I see where the water drains out on the backside of the 20 ft. wide dam. Large trees sat on top of the dam and spillway which I recently cut down. I do know the reason for the leaking is the large caverns these roots have caused. I can't afford to redo the whole pond and a farmer suggested laying a piece of 10' X 100' rubber liner across the dam area and down below the surface a few feet to stop leakage or cover holes. My question is, once I put this down and secure it with rocks here and there, won't water just seep under it around the edges and the leaking will continue just as bad as before? <Likely so, yes> Do you think this might slow it down to a natural leakage pace? <Doubtful...> By the way I do know cutting down the large trees will cause the roots to die and make more ways for water to escape, but the amount of leaves falling into the pond each year is tremendous and trees and root systems were hanging out over pond ready to one day fall in. I'm sure the leakage and/or holes is below the root balls sticking out. Please help, the few fish remaining need some deeper water to survive. Becky <Mmm, I suggest you "let your fingers do the walking"... have some local contractors (likely to be found under "landscaping" in the Yellow Page Directory)... and have them tell you your options. Maybe a clay-based material can be dished into your "over-burden" (the unconsolidated material on the pond bottom), or this overlain over the base of the liner on the dam... Bob Fenner> sp;

How to keep water in my pond 9/13/05 Hi <Hello there> I recently completed my pond project and tested it with water the other day. I laid about a 2 to 3 inches of concrete, spray painted it and then sealed it with 2 gallons of Behr concrete sealer. I let the sealer dry and then filled up the pond. It drained completely over night. <Oops!> Obviously the water drained through the concrete. I am looking for a way to seal my pond so that the water stays in and doesn't drain out. Can you give me any ideas. Thank you Rick California <There are a few approaches here... at this juncture you might try a different sealant... Please read here: http://www.wetwebmedia.com/PondSubWebIndex/thoroselart.htm and the linked files above. Ultimately, you might want to go the route of applying a liner in this basin... ostensibly treating it as a hole... You will find articles, FAQs files on the WWM site, pond Subweb re. Cheers, Bob Fenner>

Pond Leakage 8/31/05 Hello, <Hi there> I have a small pond that was constructed with a concrete interior. The pond is semi-circular with a radius of approx 7 ft. I have a constant leakage that appears on the surrounding patio area. I have utilized a swimming pool paint without success. Understand that there are some paintable products on the market especially made for sealing on concrete surfaces that are completely submerged. Please advise your recommendations for such products and a potential source. I am located in Jacksonville, Fl. Thanks!!! <Please read here re: http://www.wetwebmedia.com/PondSubWebIndex/thoroselart.htm and the linked files at top. Bob Fenner>

Leaking pond - am I hurting my fish refilling so often? 8/28/05 Hi, <Hello there> We've cleaned out and restocked a pond in our new house. It's approx. 10feet by 5feet, and 3feet deep. It has a top level which waterfalls down to the larger lower level. We've put in a pump for the waterfall and a filter, loads of plants and have 2 happy little goldfish. Only problem is we have a slow leak in the liner somewhere as the outer wall (stone and mortar) is constantly wet and we're losing 3 - 4 inches a week. <Mmm... perhaps capillatory in nature... hard to fix...> We've tried emptying the pond and found a tiny hole, which we repaired with a cycle repair kit on the advice of our local water centre. But either that didn't work or there's more holes! <Or just a "damp" area twixt the liner and up...> Anyway, time is short at the mo due to work, so we've just been refilling every few days and as there's no time to reline it this year, that's our only option - but is it harming my fish????? <Mmm, not likely... in fact, replacing 3-4 inches per week of depth in a volume of this size is likely very helpful> Very quick 2nd question, sorry - one of my goldfish seems to chase the other smaller one a lot. <Happens> At first I thought they were playing, but today I noticed light patches on the rear sides of the one that's being chased, where the nose of the chaser rubs his skin. Is this normal behaviour, are they fighting, playing or even mating??? <Mostly the latter, the middle as practice... I would add a few more goldfish to diffuse the aggression here> Thanks, Allison Franklin (UK novice pond keeper) <Welcome, Bob Fenner, old-timer>

Have you heard of a powdered pond liner 8/17/05 I would like to know what this product is and how to use it. If you have any information on it. I would appreciate it. Thanks, Sylvia <Mmm, there are materials like powdered lime, clays that are sometimes (though less frequently as time goes by) turned into existing soil to make a water-proof or more water-proof barrier... What is the application here? Something very large? Bob Fenner>
Re: Have you heard of a powdered pond liner 8/20/05 This stuff looks like sugar granules. You just put it in the pond and circulate the water. And it stops the leaks. I put it in the pond today and the water looks like syrup. I sure hope it settles. Sylvia <Yikes, I sure hope you read the instructions, precautions. Bob Fenner>

Cement Mortar You recommended that cement mortar be used to construct ponds and falls. Unfortunately I didn't and maybe you can advise what to do. My questions are: 1) Can I apply a coat of cement mortar over DRYLOK? I made my pond with Quikrete Portland Mortar mix and it leaked, so I coated it with two coats of water-based UGL DRYLOK. <Mmm, well, the new cement "plaster" coat will have to be thick "enough"... and I would add a white-glue binder to it... and I would use Dry Lok's "Etch" product per their instructions... it can be done, but... is there a reason?> 2) Are the Plastic Mortar drying characteristics similar to regular Portland mortar? Specifically, minimal shrinkage when drying? <There is some to be expected, unfortunately... I would seek out the better "plastic" cements here... they have far less alkalinity, shrinkage...> Any suggestions are welcome. I only wish I had read your website before building my pond. Thanks in advance, Ed <Mmm, am wondering what it is you hope to gain by coating over the Dry Lok... is it to add a color... if so, there are other ways... Is it because the basin/s are continuing to leak? Bob Fenner>

Cement Mortar, Follow-up Bob, thank you for your prompt response. Yes, basin is still leaking. Frustrating. <Yes... have been here. No fun> I waited a week after applying the second coat of DryLok dry before filling the pond and touched up any areas that looked suspect. First filling of pond was done 6/22 (2 days ago) and I am presently waiting to determine at what water level it stops leaking. I did add some color to the DryLok, a light brown, but the pond, I think, would look better if it was a darker green or umber color. It seems too pristine at present. Opinion welcome. <Will turn to darker anyway, so I agree with you re coloring all in the process... Please do read on WWM re such repairs... It might be best to bite the proverbial bullet here and treat what you presently have as a mere "hole in the ground" and build a new pond... with liner, reinforcing mesh, concrete... over it. Bob Fenner> ...Ed

Sealer for stone pond I need a product to seal the inside of my fish pond that was constructed out of mortar and stone. I have tried Hecht clear sealer and also caulking that is fish safe but seems as though 3 coats don't work and caulking is coming loose. Any suggestions? <Yes... though not likely what you'd like to hear. Unfortunately there just are no sealers per se that will make a "good", permanent waterproof seal twixt a cementatious wall and stone... the differing matter has dissimilar properties... expansion for one. What you are faced with are a few possibilities... the most drastic of which will/would grant you the surest repair... This is rebuilding the pond basin/s taking out the rock, laying in a liner (see WWM re) placing the rock (on carpet or concrete if very large/heavy or sharp) and re-concreting... Otherwise, a new shell can be constructed over the existing, including over the rock a bit beyond the water level... Or leaving the water level below this currently... Or... the worst, converting the pond into something else. Sorry to be the bearer of bad news here, but as you'll see from reading through WWM, I/we designed, installed and tried to repair many such water effects over the years... these are your options. Bob Fenner>

Leaky Pond = Heartache Dear Bob, <<Marina in his stead today.>> My man-made rock pond has a huge leak which we can't find. We drained the pond and I would like to close it. <<I understand.>> There are huge boulders and we would need a crane to hoist them for disposal. <<Or, create a rock garden? Lovely, with lichens growing, mosses and ferns tucked in here and there, small flowering plants, can be lovely.>> My question is: Since this pond is abutting my patio I would like to just cut out the liner and fill in with soil and landscape around the boulders; however, I keep thinking this hole approx. 15' x 10' will end up being a swamp and a breeding ground for mosquitoes. <<As one who mosquitoes find extraordinarily tasty, I am quite sympathetic to this fear.>> Adjacent to this pond is a larger pond which seems to be intact which I thought I would keep. <<Are these ponds tied together in any way? Is it possible to separate them (I'm talking about no water getting from the pond you're going to keep to the pond you're going to drain)?>> My husband maintained this double tiered natural rock pond for 18 years. We rebuilt it once because of leakage and can't afford to do it again. My husband suffered 4 strokes and is completely bedridden and I am faced with this dilemma. <<I'm sorry to read this, I understand how troubling this is to you. I hope therapy is helpful for him, you.>> My friends and family haven't a clue how to help me. I don't have anyone who really cares enough about my problem to help me so I must figure it out for myself. <<Well, if they're physically fit they can certainly help you rip out at least the bottom portion of the liner. After that, if you can line the bottom with gravel for drainage. That should help tremendously in preventing the swamp from forming. If all are unable, then I would suggest trying to find a service or handyman, laborer who can do this for you.>> My plan is to cut out the liner letting the boulders intact and just filling it in with soil (maybe some sand) and then letting it settle for the season adding more as needed and then replanting with ground cover. <<Yes, should work, but use a layer of gravel to be sure of proper drainage. Or, when the liner is out, fill partially with water and see how long it takes to drain. If the soil underneath is very compacted, then you could end up with a pond whether you want to or not (this would rather negate the leak at that point, yes?). If this is the case, then mosquito-fish and/or drab colored goldfish would be my next suggestion.>> Right now we have had several days of thunderstorms and it has about a foot of water in it. I know I can't leave this stagnant water in so I need to do something quickly. <<Quick fix is those fish, feeder goldfishes, or even feeder guppies would work in preventing the mosquitoes (I just discovered that the bed of my father-in-law's truck is where our plague has been developing) <scratches another bite>.>> Any suggestions you might have would be a comfort to me. Serenity, Lorie Shott <<Lorie, if that water doesn't drain, then I would surmise that your leak may not be too problematic. Of course, I cannot say this with any degree of certainty, not knowing the layout of your property, pond, etc. Sears (and others, but I'm tired of Home Despot) does sell sump pumps, if you need to get this drained quickly then I would suggest of one of these (though the fish are decidedly cheaper, don't have to be plugged in). Then, when the liner is gone, break up the soil, put in a layer of gravel (probably 6" or so should do). You may wish to contain the gravel by placing one of those weed liners on top (shade cloth would do the trick, too). Then sand, soil, et voila. It's time and labor intensive, that's where your family and friends can really help. After that, I would keep track of how long it takes for the soil to drain, and plant accordingly. Best of luck to you, your husband. Marina>>
Leaky Pond = Heartache? No, Leaky Pond = Garden, Answers Found Oh My God! Thank you ever so much... Your suggestions are heaven sent! You have reassured me that I can handle this. <<I am very glad, and happy to know I have reassured you, helped in any way I can. I could see that the potential for this being a great source of stress, and you need your energy to be focused on you and your husband, not a mosquito factory.>> Would never have thought of putting the gravel down first and what an excellent thought of putting in the goldfish to help with the mosquitoes. <<Ah, I come from a land that is dry, yet has no drainage.>> I can transfer some from the adjacent pond. <<I bet if they've been in there even part of the season some have yet found love and made you some little fish-babies.>> And, yes... the upper tiered pond is working well and not draining into the lower one. <<Perfection.>> I have transferred the filter from the lower pond into it and it seems to be intact and running well with the waterfall operating and nothing going into the lower pond (I must just be careful to keep it at a pre-determined water level). <<My mother and I are fans of using a stick to measure liquids in large areas. One of my great aunts still has one in the gas tank of one of her old cars.>> You have certainly made my holiday and I can stop worrying so. <<Well, THAT has certainly mine!>> Fortunately, my husband has all his faculties and wisdom to boot. We are both close to 70 years young and when I told him yesterday how worried I am about the pond he woke me up by stating "you will always have problems, that's "life".... what you want is "heaven". That put this whole ordeal into perspective. <<Very wise, indeed. I have a sister who has always reminded me to keep things in perspective (and decide what my priorities are) *first*. I am happy that your husband can still communicate, as it's been my experience that the ability to communicate means more than anything else any injury to brain or body can take away.>> Thank you soooooo very very much....you have been extremely helpful and I feel 100% reassured that I can now proceed with a plan. Serenity, Lorie Shott Lebanon, Pa. <<Lorie, as I mentioned above, I am very pleased that I have helped you, to know to what degree I've helped pleases me even more. Honestly, it's helping folks such as yourself, with a real need, that makes doing this

Aquatic Gardens Ponds, Streams, Waterfalls & Fountains: Volume 1. Design & Construction Volume 2. Maintenance, Stocking, Examples V. 1 Print and eBook on Amazon V. 2 Print and eBook on Amazon   by Robert (Bob) Fenner