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

Bottom Drains... Ponds     7/1/13
How do you connect bottom drains to filters?
If your pond has sufficient surface skimmers, will the pond still need a bottom drain?
If you have a bottom drain, will you need any surface skimmers?
Thank you.
<Please keep reading through the "Pond Section" of WWM as you've been directed. These questions and many more that will come to your conscious are covered there:
http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm
B>
Pond Bottom Drain Pipe    7/1/13
How do you install piping for a bottom drain in a pond?
Thank you.
<Same answer>
Plumbing for a Bottom Drain    7/1/13
What do I need to do to connect a bottom drain for my pond to a sewer?
Thank you.
<Same answer>
Oops! My question before I asked it!    7/2/13
Are bottom drains necessary for goldfish ponds?
<Mmm; no; but a decidedly deeper area to accumulate mulm, detritus, leaves... for easier removal is a good idea. B>
Bottom Drains 2    7/2/13
Are bottom drains useful or necessary for all ponds?
Large ones?
Small ones?
Medium ones?
<I would have; we did build in; such drains into all basins of more than several hundred gallons... Not necessarily for intakes for recirculation and filtration, but for flushing and periodically completely cleaning. B>

50 year old concrete goldfish and Koi pond -new drain question 11/5/10 Thank you for such an informative website. I have read most of the information and have a somewhat unique situation. I've lived in my home in Oregon 32 years. The 600-gallon concrete pond was here when I moved in. The pond is 14 feet long, semi-kidney shaped, and is only appx. one foot deep (below grade). <Too shallow to be of functional use as a biological system> (Don't choke - I have six large healthy Koi and some goldfish for many many years in this shallow space!) There is a crack crossways in> the middle. Over the last 32 years I have patched the crack every few years with various methods including 2-part resin or hydraulic patch. I have now patched the crack again with hydraulic patch. And now, after all these years, I want to make the pond deeper by building forms and pouring an 8" thick concrete wall above ground, 18" high, and tying it in with the existing concrete pond's lip with rebar and also digging out from underneath the lip so the concrete pours under and around - incorporating the lip for more of a solid footing - and then cover all with an epdm liner. <I'd put the/this liner under the concrete (and wire mesh)> I have received a bid for this construction and am close to accepting it but am doing final research and preparation for the "details". The existing 50-year-old concrete pond has a one inch i.d. iron pipe drain (that I've always kept corked) which is appx. four inches below the rest of the bottom of the pond. I would really like to take advantage of this lower area by cutting another hole (removing the 1" pipe) and inserting a 2" pvc drain pipe that will lead to a buried settling chamber (same depth and height of the pond) from which water would be pumped by way of a submersible pump which is suspended appx. 1/3 down from the top of the chamber. Water pumped out of the chamber will go to an upflow biofilter, then overflow back to the pond. No waterfall (at least not now). Though I would love to have this 2" drain, I am also very scared of it leaking. The drainpipe will go through an epdm liner, underlayment, concrete, and then into the settling chamber. What is the most secure method to attempt this retrofit with the liner and concrete that guarantees that it will never ever leak? <To lay the liner down over the existing basin AND the new upper wall... run reinforcing mesh over this... mortar over this... and for the pipe, to cut slots and an X over it, drape the EPDM over the pipe, Panduit and band-clamp the liner over the pipe, and pour a good 3-4 inches of mortar around and over this area. Solvents won't work here> Or should I, for anxiety's sake, forget the drain and simply pump out of the pond as I have done for 32 years? <Up to you; I would have a drain myself> I also want to have a floating skimmer to catch leaves before they settle. Up until now I have never had a skimmer. Leaves and debris sit and rot on the bottom of the pond. Perhaps simply having a skimmer would be adequate for the purpose of trapping a majority of the debris, thus eliminating the need for a bottom drain and settling chamber? It is a dilemma for me, and I am not good at choices like this! Thanks ever so much for any help you can offer. Shirley in the Pacific Northwest <BobF in N. Viti Levu, Fiji> 50 year old concrete goldfish and Koi pond -new drain question Dear Bob, <Shirley> Thank you very much for your reply and comments. I would like to clarify one thing if I could: <Let's see> Your statement "To lay the liner down over the existing basin AND the new upper wall... run reinforcing mesh over this... mortar over this..." To recap - I have an existing shallow concrete pond. I am going to build the sides up an additional 18" with concrete. I will end up with a concrete pond, 12" underground and 18" above ground, equaling 28" deep, all one (semi-smooth) surface inside. Are you meaning to then put mesh on the entire inside (over the old and new concrete) and then put a layer of mortar over all of it? <Yes, w/ the liner underneath> Does the epdm liner sit on the mortar better than it would laying on the concrete surface? <... Read here: http://wetwebmedia.com/PondSubWebIndex/linerspdconst.htm and the linked files above> What is the purpose or advantage of the mortar? And, I forgot to mention, I plan on having at least one layer of commercial pond underlayment or equivalent so the epdm liner will not come into direct contact with the concrete. I decided not to do a "normal" bottom drain, but I came up with another option that I've been passing around the online pond community for feedback. I attached a diagram (I tried just pasting it onto this page but it wouldn't work - I hope you can open the document). <I don't see it attached here> The only thing different I'll probably be doing is not having the skimmer tied into the same pump as the drain - I'll be putting it on a separate line and pump. Anyway, the pond and settling tank equalize water levels by way of the upside-down "U" 'drain' pipe, similar to if the drain was on the bottom and gravity fed. I figure a little extra pull would be enough to pull up the fish waste. <Better by far to have a "settling basin" tied into this deepest drain area... NOT to pull water for recirculation from here... See WWM re pond plumbing...> I know this is unconventional. I will experiment with it and different setups until I get something that works. Thank you again for your feedback from Fiji! Shirley in Oregon <Bula! BobF> Oh, I do see/find your graphic and I do totally agree w/ the concepts presented. Thank you for sending it/this along. B

Re: 50 year old concrete goldfish and Koi pond -new drain question 11/6/10 Oh, OK. My mind was blocking what you had written, and now I remember reading this (mesh and mortar over epdm liner) on WWM. <Ah, yes; SOP, standard operating procedure for the majority of basins we installed> I spent a few hours one evening reading everything on the website (and two other sites), <Easy (for me at least) to become confused w/ so much, disparate intake> but that was a couple weeks ago and my mind is now waterlogged. <Heee! Mine as well; from diving so much this past week, too much in the way of fab meals...> At this time, I will probably just have the liner for ease of installation and time constraints. I can always come back and do the mesh and mortar coat later if I want. And thank you very much for your encouraging words about the diagram and plans of my contraption. <An excellent symbolic representation of what a generalized plumbing scheme should be for biological ponds> I am fairly confident about the overall concept, and it can all be adjusted where needed; my only crucial decision right now, before the wall is poured, is what size pipe to put through the wall (at the old pond level). It needs to be large enough so that when I install the inner and outer pvc extensions, I won't be saying "I wish I would have made the pipe in the wall larger..." I can always scale down to the "pull-drain", which I had decided upon 2" but now I am tending toward 2.5", keeping in mind that the smaller the diameter is, the more pull? <In practical terms, not so much of import; 2- 2 1/2 will do fine for the gallons involved and equi-level draw, pump applied> Of course, depending upon what gph pump I get. It's all experimental since it's a unique setup. I only have my 500 gph PondMaster Mag-drive submersible/external pump that I've used for 18 years, and a 640 gph Little Giant (not mag. drv.) submersible/external pump that I picked up at a yard sale for $5 - thought I could use it somewhere outside, maybe for the skimmer. <Mmm, this pump won't likely "drive" such> Anyway, I know I will need to purchase a new pump and getting all of this planned out and then actually buying something is daunting. I am tending towards a PondMaster 1800 gph (3/4" outlet) or 2400 gph (1" outlet) Mag-drive for the settling tank and I can scale down the outflow if needed. <Mmm, a remark I should make re your checking the amperage draw, likely cost of continual operation> I might need to split the outflow so that the water in the bio-filter tank isn't rushing through so fast that it doesn't have a chance to do it's bio thing??? <Mmm, not likely a real concern here either> I've read about dwell times and that's one more thing I'm trying to mix into all of this. Too many things to think about! I'm trying to learn as much as I can before I get my feet wet. Thank you again for your quick responses and information. If I didn't have the internet with which to study, learn, and correspond, I would be up a creek! Ah, too many water jokes! Shirley in Oregon (~_~) <You're doing, ah, swimmingly. BobF>

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>

Opinions on a bottom drain, please, pond pb, pump sel. 3/29/10
Hi Bob
<Howdy>
A friend bought a house with a small pond. The builder had installed a conventional pool-type skimmer in the side,
<Mmm>
but the bottom where you'd normally see a 1 1/2 or 2" pipe fitting had been cut completely out and the skimmer simply dumped water into a Rubbermaid trash bin that had been buried to ground level.
<... am wondering for what purpose?>
He then put a Rio 32HF
<... see the Net re the manufacturer (TAAM), this line... I would make sure this pump is wired through a GFCI>
submersible pump into that trash bin. Essentially what he did was add an antechamber to the pond that was supplied through the skimmer.
It was interesting, but when we recoated the pond, I replaced that arrangement with a conventional pool-type skimmer that was plumbed into a Pentair 1/6 hp centrifugal pump with leaf basket, etc. and sent that output on to the filer.
<Much better, though not my first, second, third... choice in pumps>
I installed a Tee fitting inline (before the Pentair) and plumbed a separate MagDrive 12B pump with it's own line to the filter so that I have a "day" pump that makes an attractive waterfall and a night pump that simply circulates what's necessary to keep up the filtration.
<Neat>
Although it works exactly as I expected, it SEEMS that the only real change is that I changed a water flow of around 1900 GPM to a flow of around 2100 GPM while increasing the power consumption from 115 watts to 404 watts --
<Yow!>
all for the sole purpose of having an "above water level" pump. I can find a dozen or so 'aquarium-style' in-line pumps that push much more water for far less energy and the only actual consideration is that the inlet must be positioned below that water level.
<This is the better arrangement... though a couple of "decent" check valves on the intake side can serve...>
I'd be interested in your opinion on that -- especially when the Pentair is only "self priming" if you first fill the leaf basket chamber in the first place.
<Yes>
Next/Last is the drain: What I didn't do was put in a bottom drain and the reason I didn't was because I've never been satisfied with the plumbing arrangements. The combination of vales needed to manipulate the flow between top and bottom never seems to be quite right, always in need of adjustment -- and even in the pool environment, where the rule is to simply provide more suction than the skimmer and bottom drain combined can supply ... I still see marginal results. So I'm toying with the idea of putting in a 3 inch drain in the bottom of the pond and running the pipe up and through the bottom of a Rubbermaid trash bin sunk to grade level. I'd then use an inexpensive submersible pump in that well to run yet another separate line to the filter. I'd be interested on your opinion on that, too.
<Mmm, do see my posted mat.s on pond plumbing:
http://wetwebmedia.com/PondSubWebIndex/pdplumbing.htm
and the linked files above. I would not "draw" the water for recirculation from the bottom itself... Unless you can/will divert this in turn to the "sump" trashcan/Rubbermaid for venting the bottom water and solids to waste in turn... Better to leave the last few inches undisturbed in all but the smallest biological water features... for "bad water", solids... to be vented to waste during periodic maintenance in the warm/er months>
Asking my local pond professionals what do it is often like asking the scarecrow which road to take to get to the Emerald City - I get a dozen ways it can be done, most of them I already knew. The problem is that the only WRONG ways are the ones we look back on after we learn what we didn't know.
So - What type of "main" pump do you recommend for an 1800 gallon pond?
<See the WWM site and elsewhere re the "Sequence" series... a fractional HP of one of these... likely the 1/6th...>
How do you feed that pump from the skimmer?
<Gravity... putting/placing the pump subgrade... look into building or buying a pre-made vault. With any luck, an irrigation box will do here>
How do you plumb the bottom drain, if any?
<... Oh boy... really should be done twixt the liner and the wire mesh/cloth and concrete... Now... it will show... can be "looped" over the side (rather than plumbed to the "main drain" (anterior) fitting in the pool skimmer... There are drains of plastic construction made for such... better to buy, fit one of these with flexible PVC...>
Thanks in advance
<Welcome. Bob Fenner>
Re: Opinions on a bottom drain, please 3/29/10
Thanks --
<Welcome>
One misunderstanding: I've drained and chopped the pond to make it bigger (these mutant Koi just keep growing!)
<Heeee!>
so I'm correcting the problem(s) I created last time (pumps & drains and a settling chamber) but what I really want is for once in my life to get ahead of the curve and not immediately see what I should have done this time!
<Very understandable>
A vault that is water tight -
<Or has provision for some water getting in... draining or being pumped out>
bottom below pond level, upper lip above water level would house a Sequence pump. What I'm shooting for is gravity feed to the inlet, yet dry on the outside, correct?
<Yes>
What I read on the site regarding bottom drains is that they be "Tee'd" into pipe from the skimmer so that both feed the pump with a ball or knife valve on each to control and divide the flow. I understand that convention, but hoping that technology had advanced.
<Not as far as I'm aware, no>
Finally re: the Rio pump and GFI ... does anyone connect anything to a pond without a GFI??? I'm not sure it's even legal anymore!
<I would hope it is not. Still, I wouldn't use a Rio pump... period>
Thanks again
AB
<And welcome in turn. BobF>

old farm pond-old rotting steel standpipe- Replacing Pond Standpipe 5/11/08 Hello Robert Hope you are well. <He is, diving in the Red Sea presently with limited web access. Scott V. with you tonight.> I have 3/4 acre pond and the water level keeps dropping because the standpipe is rotting. It is 6 inches in diameter. I'm hoping to dig down about a foot or two and find good metal and cut it off, then replace it with a rubber boot and 2 or 3 feet of PVC to get back to original water level. Thanks for any thoughts, suggestions, James F. <Not much to say here, your plan sounds fine. You will need to cut back to good, non corroded pipe and replace. PVC is a much better choice per the application. A potentially big job, just make it fun, it can be!>

Pump Plumbing, Pond 4/7/08 I've got a 10,000 gallon pond that I'm re-plumbing. Here's what I have to work with so far: Atlantic Tidal Wave Pump (9,000 GPH) Submersible Large Savio Skimmer Large Savio Filter Falls (with 22" weir) The pump is in the skimmer now and feeding the Filter Falls which feeds an upper pond and two streams. The pump is also feeding a large waterfall. I want to put in a retrofit bottom drain in the pond and pull from the drain using an external pump (Sequence 1000 series) with between 4300 and 5800 GPH capacity. <OK> Can I feed the pressure sides of the Tidal Wave and Sequence into the same 3" manifold that would then feed my waterfall and filter falls unit? <I would not, the larger pump will likely out power the smaller. Ideally each pump will have its own plumbing.> The pond is about 5 feet deep, the Sequence would be level with the pond surface. The water fall is 4 feet high and about ten feet from the manifold. The filter falls would be about 5 feet vertical and 20 feet of pipe. I'm planning on 1.5" going from the manifold to the filter and 2" going from the manifold to the water fall. I'll have 2" going from the Tidal wave to the manifold. I'll have 1.5" feeding the sequence and 1.5" from the Sequence to the manifold. Does this all make sense, or should I consider a different configuration? Thanks, Neil <I would plumb the Sequence output up with its own dedicated line. Also, if the input of the pump is not at or below the water level of the pond it will need to be primed each time it starts up. It is better to place this pump a bit lower in relation to the water level, these are not suction lift pumps. Be prepared for fairly frequent cleaning with a bottom drain configuration. Welcome, I hope this helps out. This sounds like a very nice pond. Scott V.>

Pond Filtration system... lost prime - 12/13/07 Hi, I just bought a house and inherited a pond, it doesn't have any fish or anything in it. The filtration system in the pond was working when I bought it, but it suddenly stopped working. <... can you describe this filtration system? What stopped "working"?> I got into the pond cleaned out the filter in there, checked the filter next to the pump and cleaned it out, and I also checked to make sure the pump is working. I started the pump after cleaning and the water is not pumping through. I can hear the pump churning but the water is not pumping. I think its an upward filtration system. I was wondering what do I need to do re-start the system, do I have to fill it with water to pressurize the system ? <You may have to prime the intake, pump line... Can be tried in a few ways... jamming a pump hose/hose pipe up an intake line with someone to turn the pump on while you're doing so... filling a pump intake trap... pressurizing a line in a skimmer/box intake... I would NOT leave the pump running without water going through it for any period of time... IF necessary call in a pool or pond company and have them show you how to re-fill the plumbing lines. Bob Fenner> . Thank you Mal

Re: Pond Filtration system 11/13/07 There is a filter in the pond just a plastic cover with holes to keep debris off <Ahh... this is most often called an "intake screen"> and there is a pipe that flows upwards, and it reaches my pump where there is a second filter before the pump. <All above water level I take it> and from there another filter on the other side of the pump before the water empties out into the pond through a water fall. The pump I believe stopped pumping because it had debris in it. so I cleaned everything and fixed the filter( the one in the pond let debris in). I took out the pump cleaned it, turned it on and saw it spun. <Good> so I put the system back together to see if it will work at which point it didn't. so I stopped the system. I was worried I might damage the pump without pumping water, but I think its okay. There is a few tubes on the water fall side of the filter, and I also need to check the filter before the water fall. I think I will be able to use a hose to pressurize the system before I turn on the pump, thanks for your input. Mal <Welcome. Please do read here re the use of check valves: http://wetwebmedia.com/PondSubWebIndex/chkvalvpds.htm and the linked files above. Bob Fenner>

Pond... plumbing, shape design... 10/3/07 Hi folks, I respect your request for avoiding questions that the user could find in the FAQ or with Google. I found your site with a Google search and I don't see my question answered anywhere yet so hopefully, I am not creating undue burdens here, and thanks very much for setting up the space to ask. <Welcome> I am now facing taking over someone else's project at mid point. The contractor apparently had a shady side and is now in jail. <Yikes!> Looks like promises were made and not kept about what was ordered, etc. I was looking at the hole he left last night and I am researching all I remember from my own pond building and pond maintenance days and my landscape design classes to see what I would need to pull this off. I used to work for a relatively high end pond and water building firm in the DC area. I dug holes, moved rocks, ran equipment and most especially did lots of maintenance on filters and ponds. I never felt responsible for designing the whole thing, engineering the plumbing although I have certainly fixed broken pipes, valves and pumps. And I have some awareness of waterfalls, stream beds, construction and (gulp) leaks. I have also installed some small features for friend's and I usually build my own filters to sit in the pond. This project will be one, or two steps beyond what I have already done. And, I haven't been in the business for over ten years so I am internet researching to job my memory of what we used to do. <Okay> The size of the pond is roughly 15 x 30 feet. On the deep end it looks to be over 6 or 7 feet. <Good-sized... what do the folks in charge "want it to do?"> The pond is roughly kidney shaped and it is already dug out. The contractor left a layer of plastic sheeting over it like a liner, I don't know why. The homeowner said the contractor said he did it to dry out the ground (?) <?> Is this a technique that sounds familiar to anyone? <No> First step would be to remove it as I am going with my experience installing the underlayment and the EPDM liner. <Good> The first thing I notice is there is no work started yet on the plumbing, no skimmer, no trenches or pipes, no bottom drain. So my first question is, common sense from a maintenance background is to install the bottom drain. There is no hole or trench dug for a bottom drain so I have to take care of that too. But I need to research how that works. I have seen it working but I can't remember "how" it runs. I am a little confused with all the different installations I was a part of and I hope I am not mixing one idea with another? I have seen skimmer boxes with the pump inside them. <Mmm, really?> In that case water is sucked into the skimmer and pushed through the pipe up to the bio filter which doubles as a waterfall top edge. <Have seen these...> In other systems the filter or filters are vortex, bead or other external variety, usually with high nitrate producing Koi, are outside the system and isolated a bit to take the pump sounds away from the pond design. I think this would be over kill on this design for what the customer wants. <Good units... pricey to acquire and operate, but work> I also know there is value in adding a waterfall pump and having a regular circulation pump. This allows energy savings when you want to keep your system filtered and healthy but not pay the electric bill or possibly generate noise all the time with the full force of the waterfall. It also allows for maintenance and adjustment to the waterfall without hurting the pond system. <Well-stated> That's what I know. What I don't know is about how to set up a bottom drain and valve it to the flow of the skimmer? <Mmm, can be done through the membrane (with flanges) or inside... via trenching in both... the main drain plumbed to the skimmer directly if one wants... with the second/behind hole going up/out of the system to the pump intake... but I encourage you to have at least two intakes... if you want a skimmer (or two), plumb these AND the main drain separately out, up to the pump...> If I take on this design, I am thinking that the pump needs to pull water from both the bottom drain line and also the skimmer. <Yes, this is best> If true than the design with a push pump in the skimmer would not work. <Correct... and I am NOT a fan of submersible pumps...> Is this true? Therefore if I used a bottom drain I would look at designs with the pump in the biofalls or free standing outside or behind the waterfalls. I would need one of these designs to achieve puling the water up the button drain and the skimmer, yes? <Yes> And if I am on the right track there, then I will need a valve to adjust the rate of intake between the skimmer and the bottom drain, Yes? <Correct> If I read correctly, there is a reason to completely shut off the skimmer if necessary to feed the fish or for skimmer maintenance and if I designed it correctly I could just valve to the bottom drain 100% with no worries. Yes? <Yes> Can someone please refresh my memory as to what is the usual percentage of flow between bottom drain and slimmer to the system? <Mmm, less to the skimmer/s... ten-twenty percent or so; the remaining from the main> Assuming that in large part this is something you observe once it is running but there should also be a rule of thumb here. <Yes> If I read on line articles right and compare that to the ponds I have installed in the past, I believe you don't want the water fall or pond return flow too near the bottom drain, for achieving good circulation mainly. But that is how the contractor has set it up so is this something I should really consider doing differently or is it really going to be a problem? <Not likely a problem> I should mention that although I see the wisdom of a bottom drain, if it turns out to be out of the homeowners budget or not completely necessary, I want to consider the design without this feature. I assume this takes me to the simplest solution mentioned earlier of putting a pump in a skimmer box and running a single line to a biofalls. Yes? <... not if it were my design, no. Much to be related here... the best engineering involves a "passive" system of plumbing that conducts water NOT from the bottom, but maybe 3 or 4/5s the way down... this water recirculated... and a bottom "drain" in addition to simply dump the "bad water" from the bottom itself...> The other question I have, also important, is about pond construction. This is Denver. I am writing this in early October so I may have a month left before the ground gets too solid. Or, I could have two months let, you never know around here. I am sure there must me what we called frost heave back in Virginia, here in Denver. YOU have to build with a mind to the changes in the soil when it freezes and thaws again. <Yes> With that in mind I want to ask about the technique that I remember using and ask for some feedback to see if what I am thinking of doing, makes sense to an expert? <Sloping sides, good landscape drainage, perhaps a sand bed arrangement around the basin, not leaving the system empty during freezing weather> I am used to digging more or less vertical walls in the dirt and taking the top 18" down for setting one or two cinder blocks, depending on the strength of the surrounding soil. We laid the cinder blocks on the side and filled the holes with tightly packed dirt. Then we rammed pieces of rebar into each hole. We built some very nice high end designs this way and while it stabilized the bank, or seemed to in the Virginia clay, it also was a way to provide a stable base for large heavy rocks that could be put next to or on, an edge. <Sounds very good> I see lots of "how to's" on the web about building cinder block walls form the bottom of the pond, but none using the techniques I am remembering. <I am unfamiliar with this as well> The contractor left long sloping edges that I don't like very much. They slope nearly 45 degrees around the shallow end. <Mmm, yes... not good for maintenance, but better to avoid having the basin crushed, pop-out during coldest weather> It seems more natural to my mind to cut the edges more to a vertical angle, possibly leaving ledges (yes knowing about predators and ledges). Is there any reason a design would have such largely sloping edges that I am not aware of? It also seems more potentially stable to make a proper wall at the start. And that means pretty much vertical with soft rounding on the bottom edges, more art than science but then, I have been there and done that before. <As stated> Thanks much folks. I know I am asking a lot but I hope my questions have provided enough clarity for answers. I would recap this into wall constructions with cinder blocks on the top layer only and bottom drains and system choices for pond mechanics. If you post my question and your response please omit my phone number and email. Thanks. David Groover <Am unfortunately going to be out of Net reach for a couple of weeks soon... Bob Fenner>

Question about sick pond goldfish... Mmm, and Pond Circ., Filtr., Maint. 8/7/06 Hi - I could not find the answer to my question on your web site and hope you can help. <Will try> We have a natural outside pond. It is under shade all day and has much foliage around it but none in it other than the occasional foliage which drops in from around the pond. The pond measures apron. 26 ft by 14 ft by 4 ft deep. It is always clear and is fed from the runoff of our spring box. <How nice!> The water is constant circulating and has a pipe in the middle of the pond to control overflow. <Mmm, I would "sleeve" this... put a pipe over this one, notched at the bottom... to "force" "old water" and silt from the bottom rather than venting newer water from the surface> There is a dirt bottom and a layer of leaves. Also at the bottom is a very small spring which additionally feeds the pond. <Great> I am not sure how old the pond is, we have lived here 5 years and it was here when we bought the home. The only upkeep is the removal of leaves every 2 years or so. The current gold fish we have in the pond have been there 3 years. We originally had five. <No reproduction? Odd...> Just this past year, around the beginning of spring we lost one fish and now, recently, a second. The goldfish both measured about 6 to 8 inches long. Prior to dying, they both became lethargic and kept themselves close to the edge of the pond. Resting themselves there and not swimming around at all. They also lost many of their scales and where the scales were, there was "fuzz". <Perhaps... secondary... decomposition> We are worried there may be a disease or parasite in the pond. <Mmm, not likely... or at least not likely a primary cause/source of mortality here. Much more likely is some sort of environmental complaint... most easily addressed with the added "sleeve" over your standpipe mentioned above...> We are also concerned that the problem may be at the source spring. <Mmm, yes... and/or some bit of decomposition in the "overburden"... the unconsolidated "ooze" at the bottom... again, best addressed with the sleeve, periodic increased (over)flow from rain...> This is concerning because we use the water from this spring for our home use. It is a separate spring box pumped to our home but the overflow from this spring feeds the pond. <Mmm... Am sure you have particulate and chemical treatment to make this safe, potable... If it were me/mine, I would make use of a reverse osmosis device for potable uses... adding a "booster" pump for need pressure if required...>> Any help you could give would be greatly appreciated. Thank you. J.M. <Welcome. Bob Fenner>
Re: Question about sick pond goldfish 8/8/06 Thanks Bob, <Welcome> Need clarification on the "sleeve". I understand a pipe over the existing pipe but please explain the "notches" at the bottom and how it allows for water and material to be pulled from lower pond depth. <Wish I knew how to make, post a drawing of such... imagine your existing overflow pipe... with a pipe of larger diameter placed over/around it. The new, larger pipe is "taller", and there are some holes, inverted "V" cut outs in this pipe at the bottom... such that, when the water level rises, the water from the bottom of the pond (about the cut outs) travels up, between the inner wall of the new pipe, the outer wall of the old standpipe... and to waste> And again for clarity - the "sick fish" problem is likely environmental? <Almost assuredly> If so, then explain how the "sleeve" will "fix" this. <By improving the environment... helping vent "bad water" (nutrient laden, low/no oxygen...) from the system> Are we likely to lose the rest of our fish before the problem is resolved by the "sleeve"? <Mmm, impossible to say. However, not worth trying to do something "overt" here... adding a large influx of water, "treatments"...> I too was surprised that we have not had "babies" yet. Any ideas on cause? <Many possibilities... mostly "environmental/water quality" probably... though could be predation... frogs, insect larvae (do you have Odonatans/Dragonflies?> Should we create "ambiance"? :) <Could... more diverse habitat would help... plants...> Or, there are babies but they get eaten. Or there are eggs but environmentally the conditions are not right for maturity. <Some should survive> Maybe I should stick to one problem at a time - the "sick fish" for now would be the priority. If we lose the rest of our fish, is there a "stronger" fish we should consider for replacement? <Mmm, would need much more information... on where you're located, the local laws, the likelihood of the animals getting loose... too many issues to speculate on w/o much more input> Again thanks for all info - and your quick reply. JM <Bob Fenner>

Pump for pond, main drain and pond repair - 06/01/2006 Hi, I have to replace my old swimming pool motor pump system about 10 years old, I have been told a whitewater 6400 gph would be my best bet, they sound expensive but I think he said it was only 2.6 amps to run, are you familiar with this? <Mmm, nope... neither is Google evidently. I generally plug Sequence series pumps... maybe this is one of theirs. The amp draw sounds about the same> Also I have a tree root puncture up close to the surface on rubber liner, I was told I could cut root out behind and fill in with concrete then put the rubber sealant on the pond side since it is close to the old skimmer and would be hard to patch. <Yes to the last> Another thing when my husband put the main drain in it's probably 2 " the wire basket collapsed over the years and since he is no longer here fix what can I put there to keep the leaves from going down the drain, the pond is about 2' deep. Thanks D <...? Need to retro-fit some sort of screen here... I'd visit pool/spa supplies re. Bob Fenner>

Recirculating materials 8/4/05 I am a catfish farmer. I intend to build a concrete pond of 8x15ftx3. Capacity is 3000 fingerlings to Grow out each. Please what are the recycling materials that i should use or better if you have your drawings, can you attach them to me. The dept is 5-6ft. thanks, and best regards. Nath Okezie. <As in plumbing and pump? There are a few ways to go here... the intakes are the biggest issue... all plumbing, fittings should be PVC... and the basic elements are detailed here: http://www.wetwebmedia.com/PondSubWebIndex/pdplumbing.htm The pump line I'd look into is "Sequence" for cost of operation, efficiency, longevity. The intakes? Can be a spill over arrangement on the upper side, or a large intake area/s with enough screened holes to accommodate flow. Bob Fenner>

Technical Drawing on recycling pond... 08/08/2005 Hello, I need a technical drawing of a recycling concrete pond of 5ftx15ftx3nos.thanks Best regards. N.N.Okezie. <Uhh, what we have is posted on our site... You might do well to invest in some of the current aquaculture works in print. Bob Fenner>

Pond Bulkhead Plumbing 7/29/05 HELLO CREW!!! Hope you are all staying cool and enjoying the summer. <Thus far> Yes, it's me again! Hopefully this will be the last pond construction question I have for you for a while. I know you just wish I'd finish it already! ;-) <Mmm, no... ponds are good "examples" of a more "appropriate", real sense of orientation... they are not "fixed point objectives", but infinite games... where the "purpose" is not to "finish" (or win), but to keep the game in play... a large part of their sub/unconscious allure... you, they will never be "done" my friend> After reading extensively through your Pond section, all related FAQ's and LOADS of help from Bob (THANKS!) I have the pond dug, 4x4's set in concrete, interior walls hung, all backfilling completed and will be doing the plumbing this weekend. <Ahh> That's where the uncertainty sets in. I have a couple of questions about installing the bulkheads for the pond. I will be plumbing through 3/4" plywood (interior pond wall) then through the LINQ Premium Geotextile Pond Underlayment then lastly through the 45 mil EPDM Liner. My idea for installing the bulkheads WAS to run the bulkhead through all 3 layers like it was one big tank wall and secure the bulkhead nut/washer to the outside against the plywood. <Easily done> But the more I thought about this, the more I realized that it will definitely cause some major leaks! If not now, at least a few years from now when the wood starts to shrink/age. So now I plan on cutting a hole in the plywood and underlayment about 2" larger than the bulkhead diameter and having the bulkhead just hold the liner. Is this the correct way? <Yes> Is there a need for any type of adhesive/sealant between the gasket/washer and the Liner? <IMO/E, yes... a smear of 100% Silicone (can be gotten from Home Depot...) on all succeeding contact surfaces... the bulkhead face, gasket/s, the nut...> When plumbing the bulkheads for the drains and returns I am planning on installing the liner first, then filling with water to just below where the bulkheads will go to make sure the liner is flat and spread out so as to not have any downward strain on the plumbing/bulkheads after the pond is full. Then run the bulkheads and tie in to the plumbing. My theory is that if I just lay the liner in and get it held down in the corners, then plumb it, <Better to "practice fill" with the liner in place...> when I fill it with water the liner is definitely going to settle/shift some since the water will be pressing into every nook and cranny whereas I would not be able to compensate for that manually (plus it gives me an excuse to jump in the pond when it has water in it! HA!) <A good idea> Hopefully these plans will work and I can get moving. I really need to get the Koi in there so they can get settled before the cold weather hits. MAN! This summer is just flying by! <Tempus fugit indeed my friend> Thanks for all the help and keep up the good work. I hope to be able to meet you all some day and "buy a round or 2". Tom (The Tool Man) <Look/ing forward to all. Bob Fenner>

Pond Plumbing Good evening, my fishy friends! I hope all is going well with you. <Yes, thank you> First, a BIG THANK YOU! for all the help you have given me in the past with all of my tanks. Fresh, Brackish, Salt, Pond (did I leave any out? ;) )... This question is about my pond remodel for my wife. It will be a Koi pond with some plants (mostly Lilies), housing 4 7" fish. I am ripping out the plastic "form pond" of 100 gal and replacing it with a dug and raised pond of approximately 900 GAL. <Ahh, much better> I have perused all of the FAQ's in the Pond Section and think I have a grasp of it but would like to run a couple of things by you for your approval, then a quick question. <Okay> Pond will be raised above ground 22" using pressure treated 3/4" plywood on the inside and 2"x6" pressure treated wood for the outside then dug down an additional 2 1/2' or so with a liner. All of this will be supported by 4"x4" pressure treated posts with concrete every 2'. I plan on building my own up-flow filters using gravel and poly filter. All of this powered by a Sequence 3600 pump kit (Sequence 750 pump (600 - 3600 gph pump), strainer, primer pot, and check-valve). Sound OK? <Very nice> My aforementioned question is about the water returns. I plan on splitting off a small part of the return to feed a low pressure/high flow "fountain" but for the remainder of the return, would it be better to use a sort of manifold to spread the flow around the entire perimeter, or just flow it back in 1 or 2 pipes at each end of the pond? <Mmm, functionally (dissolved oxygen, circulation...) likely little difference per your design, construction specifications... Looks-wise? I think the traditional "waterfall" look will/would be best> As always, thank you for your valuable time. Tom (The Tool Man) <Thank you for writing, sharing your ideas. Bob Fenner>

Pond depth and placement of settling chamber? I've been contemplating improvements to my modest 400 gph goldfish pond and water garden, and I am thinking of installing a bottom drain plumbed to a settling chamber. <Good idea> does the depth of the settling chamber need to be as deep as the pond? <Mmm, no... depending on where it's located, I guess what you consider a "settling pond"...> I know the top needs to be at same height as max water level in pond, and gravity pushes water through the drain to the settling chamber, and this chamber then acts as a sort of pre-filter for the pump. But if the chamber is only half as deep as the pond, will it still function as desired? <Ahh, yes> also, should I put a ball valve to close off the settling chamber for maintenance and muck out, or could I just use a length of standpipe that would be higher than pond level (this enabling draining of just the chamber)? <Either one will/can work... the stand-pipe is my first choice, though this can be problematical if children, animals, other folks might wiggle out... good that it is not the depth or deeper than the main system... so that doesn't drain it completely in this event> would a 1200 gph submersible dolphin pump in the chamber be able to draw enough to have leaves and gunk flow through pond drain and settle out in chamber? or will I have gunk accumulation in the drain pipes that I'll need to flush out somehow? <Depends... on diameter of plumbing... size of leaves... I would screen against large material clogging, and just net off the large stuff during regular maintenance> how do you hide a settling chamber if its right next to pond? I'm thinking of using a 30 gal barrel buried with a painted lid and then have grassy type plantings around it. <Sounds good... a simple wood cover, faux rock, plantings... all work for me> thanks in advance for any advice. Chris <Bob Fenner>

Re: pond advice. Plumbing, waste lines Hey Bob, I posted this on the forums but thought you might be curious to see it as well. Have a good weekend ! Andy ________________________________________ ok, I had a brainstorming session with a neighbor, and it seems that if I get a permit (and IF the city allows it) I may be able to plumb the waste line into the sewer instead of the storm drain. <Mmm, I wouldn't involve the city, permits if you can avoid them, using the sewer line... If possible, practical, I dump my waste water on the landscaped (it's dry here)> If I am allowed to do that, it opens up new possibilities, because the level is way lower (1 meter?) so it would be lower than my bottom drains. <As you and I have hinted around, being able to pump the water down is just about as valuable... a trade off in safety vs. turning a few valves instead of lifting riser pipes> IF I can use this approach, is there ANY need to have a pump connected to the waste line? I assume no. <No> The only negative to this approach that I can think of is that if I flip the drain, the whole pond will empty... bad if I do not intend on it. <Yes> If I am willing to lose water during purging (since I am not using a vortex etc) I think it would make sense to just plumb straight from the bottom drains to the waste line. (note: I do not pay for water :) ) <... well, could do...> While I was modifying the diagrams to have this new update, I made a big change to the pumping method... I went to a single pump, which flows to both the filter and the waterfall, then has ball valves to control how much flow goes to each, so most of the flow can go to the waterfall <A definite plus... however, it is "nice" to have an alternate pump for the chance of the other going out. Bob Fenner>

Large standpipe for pond I have a large 4 acre pond and I need an adjustable standpipe so that I can adjust the pond depth from the standpipe. Something like a 20" diam. telescoping pvc pipe would be nice. I can't find one, do you know of any companies that make one ? thank you <An interesting engineering/design project. And one that is a bit worrisome, as in what might happen if the adjustability or even whole standpipe fail? I would like to be assured that there is a valve (or two) distal from the overflow from this standpipe... or absolute assurance that should the standpipe fail that all the water coming from this basin not cause damage downstream. There are a few designs that one might employ here. You can/could make a "sliding" cylinder with an overflow weir... or a riser with drainage ports at intervals/heights that would allow for keeping the water at this level... All of the sorts of devices I am aware of have been "one-offs" that folks have made for the purpose in mind. That is, not "from a company", but DIY or from help for the job at hand. Bob Fenner>

KOI Pond Construction Bob, This is Keith Slinkard , Eric's Father-in-law . <Hello Keith!> I have some question about the mods that I am going to make to the design and enlarging my fishes habitat. 1. I purchased Firestone EPDM liner and I am concerned about the wrinkles that I think I will have . I think that I want to shot crete over the EPDM ,but can not find directions as to what to do with the wrinkles prior to applying the crete . <No worries... on a nice warm day (careful not to lay the liner on your grass!) the material becomes much easier to make folds in then> 2. The size is as follows , 18' long X 8' wide X 2' deep with a 1' X 1' plant ledge around the perimeter. All walls are completely vertical . I think this will add to the wrinkles and make the shot crete application difficult. Should I angle them somewhat ? <No. Best to try and make as vertical as possible... the wire and shotcrete will conspire to make the walls and corners more sloped... In fact, a good idea to use a lower slump concrete/shotcrete mix... and "lay a bead" on the bottom corner seams in an attempt to "build up" the mass of material... much easier than "pushing up" the material after the concrete truck, applicator is gone> 3. I am going to change to a pond filter to like the one you exhibit in fig.10 of your Aquatic Gardens book on page 10 . With the volume of water that I need to move , do you suggest a dry pump, and if so what size ? <Yes, not a submersible, and one with as small an electrical current as you can get by on for the volume (at the head) you're shooting for. Please ask Eric to show you the "Sequence" series pumps... if memory serves they have a nominal 1/5 HP unit that should work nicely on your application> 4. Where do I place the supply line to the filter and how do I install it through the liner material to insure a water tight fitting . <Mmm, best to run the plumbing "inside" the liner, and up and over the side of the system (a bit tricky to prime the first time but worth it). Water for the intake should come from as far away from the return as practical... and from the bottom as well as a side intake (a foot or so down in the water), these with a valving manifold to isolate one or the other (to vent water occasionally)> Thank you in advance for your expertise and direction . Keith Slinkard <Glad to help. Bob Fenner>

Pond pump problem Dear WWM crew, <Howdy> Thanks for the great website! <You're welcome> I have a 10,000 gal Koi pond with a Aquadyne 4.4 bead filter. I originally had an external Sequence pump rated a 4800 gal/hr and this year added a Sequence 6000 gal/hr pump. One pulls off the bottom drain, the other of the skimmer. The pumps feed to the filter in separate 2 inch pvc flex pipe and connect with a "Y" fitting just prior to entering the filter. Overall head is about 4 feet. <Feeding the filter with one pump is a better arrangement> It appears that the pumps are working against each other and the overall flow is only minimally improved. <Yes> Should I plumb the pumps in series rather than in parallel (and which should be first)? <I would either alternate which pump is on (one at a time) and install one way check valves (Please see here: http://www.wetwebmedia.com/PondSubWebIndex/chkvalvpds.htm) ahead of the "Y" so the water flow/pressure is directed to the filter, OR divert (likely the smaller pump) flow simply to recirculation> Do you have any other recommendations? <A few... but need to know more about your set-up, livestock, your desires. Bob Fenner> Thanks for your help...again! Sean

Skimmer question (for pond screening) Bob, can you tell me more precisely what type of sturdy mesh would be appropriate for the skimmer in the pool-to-pond conversion? Thanks. <Yes. Polyvinyl, polyethylene. These are available from large home improvement retailers as "fencing" and sometimes in the sturdier netting to keep birds from eating your garden... as well as the aquaculture industry (we could refer people to the bigger businesses in the garden pond industry: http://www.wetwebmedia.com/PondSubWebIndex/pondlinks.htm Bob Fenner>
Re: skimmer question I am trying to help the photographer set up a shot. She wants to know what to look for -- how fine the mesh is. Are you talking about the orange or green plastic stuff sold as fencing? <Can be these different colors. Most all is black, about 1/2" to 1" mesh is about right. The photographer might also want to check with "swimming pool supply" houses for a source. Bob Fenner>
Re: skimmer question Thanks -- I've passed this on. It will be interesting to see what they come up with! ;-) <I'll say! Let me know... made submissions to Sunset Magazine years back... can/will take photos if they/you'd like. Bob Fenner>

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