High oxygen rates in a tank  1/10/17
Hello:
<Judy>
I have a 70 Aquaclear on the back of a 38 gallon. The filter has a turnover of 300 gph. Is this something that is producing a high oxygen environment?
<Likely so>
or does current help even more as in from a powerhead?
<I do encourage redundancy in aeration... and filtration>
Thanks
<Welcome. Bob Fenner>

How to slow air flow    12/9/17
I have the aqua culture 20-60 gallon double outlet aquarium air pump. My question is, how can you adjust the strength of the pump? I bought it mainly for an air toy in my aquarium and it is too powerful. I read a similar question on Wal-Mart's site (questions and answers/reviews) and the answer suggested that the only way to tone it down would be to bleed off a
little of the air with a t way connector valve or perhaps a pinhole in the airline.
<Yes to the first idea. Get/use a "three way" valve and use the controllable port to bleed off the excess pressure/volume>
I tried the pinhole idea before buying the valve, bad idea and had to replace hosing as it stopped all or any airflow.
<... not able to control>
Can I use the T way connector valve to bleed off some air to reduce the flow strength? If so, how would I connect that?
<The incoming line between the pump and the valve will "line up" with the tubing going from the valve into the tank... the controllable port (using the screw valve) that is at a right angle you'll use to drain off whatever amount of air you want. If it makes a hissing sound, you can put a short piece of open ended tubing on it or still a pipe cleaner into the valve port>
Thank you for your time,
Bryanne
<Welcome. Bob Fenner>

query.. Concern re sufficient DO, FW      6/24/17
Hi guys happened to go through your website and found it to be very informative and dependable ....I have this question related to better procedure of oxygenating water and I am really getting paranoid looking for a correct answer.....
<No need>
Of late I have realized that although I have been very regular in tank maintenance including water change , correct filtration , best food etc I still felt that my fish is just striving but not thriving in comparison to the fish I see with my friends who are very laid back on maintenance. I felt that their fish are more colorful and active then mine....Looking out for an answer I came across on many articles on water oxygenation and its importance. The studies showed that gas exchange happens on the surface of water.
<Mostly; yes>
Hence more the water agitation better...
<To an extent>
so my first question is this ....How much should it be ? For in my case I have a diy top filter like u see in these Chinese aquariums but instead of water coming out from one end , I have made holes so it comes out from the
entire filter like a spray bar ...
<Neat>
but the flip side is that it doesn't agitate the water a lot. I won't say that surface is stagnant but it doesn't agitate it like a power filter with nozzle pointing upward should do ...so do u think its still sufficient for oxygenation ?
<Likely so... are your fishes breathing rapidly, labored? >
My second question is that I came across many articles which claimed that surface aeration like the one I have is least effective method of oxygenation and bottom up method is the best like using air pump or power head.... Kindly pls help me what should I do and which method is best
Thanking you Raj
<Well, redundancy in circulation, aeration, filtration is desirable... Always good to have back up... And ask about at your local fish stores to see if they have dissolved oxygen testing gear (to ease your mind); perhaps they'll lend it to you or you can buy a colorimetric assay kit. Bob Fenner>

Gang valve for sharing an air pump with bubblers?     8/8/13
Do any of you all use one of these?  I Know not everyone does.  I'm looking for a gang valve expert. Is there a secret to getting them to work?
<No secrets. Open close by turning... Have you tried blowing through?>
I went through several plastic ones and they were junk and broke too easily.  I ordered a metal 6 valve one online and I have decent air to all the valves and the manufacturer of the Fluval Q.5 said that I could run up to 5 bubblers from it. 
<... depends on what type of bubblers and at what depth>
However... I can't even get one airstone to work but the lines blow bubbles if I pull off the stone.  It's very discouraging.  They're all turned off but not even one will turn on but when I turn one on I can get the airline but not the bubble stone to bubble.
<... Have you tried blowing through the line/s, air stones yourself? They may be of inferior quality... take more pressure than the pump can generate>
To make it worse I unplugged my large filter temporarily when a suction cup got lost from a bubble wall
<Ahh, these are pump killers... again, if you can't produce air through it with your lungs, the air pump won't be able to>
 air stone and then when I turned it back on it isn't working at all and it's new...and a good quality brand.
What happened to it?  I turn it off whenever I clean the tank.  This never happened before.
:-(
Jill
<Something like this has been responded to recently. SEARCH on WWM re. Bob Fenner>
Re: Gang valve for sharing an air pump with bubblers?     8/4/13
Never mind.  I poured water into the filter and it's working again.  And the Fluval Q.5 isn't up to speed.  I debugged the new air stones... All ok run singly on the smaller air pump.  Very weak pressure running one air stone from the Fluval.
Bummer, it looks like I'm going to need to figure out how to change the air 's air bag.  :-(  
YouTube here I come.
It's not that old and I have released pressure on it periodically.  But I guess I didn't do it often enough... It's been about 6-8 months. 
Maybe if you post this it will help someone else know what to do when these things happen.  Sometimes it's not the gang valve.
Thanks,
Jill
<Hello Jill. Air pumps are much less powerful than you think, and the deeper down you put the airstone, the weaker the flow of bubbles will be.
It's a good idea to get a bigger than you need air pump. Use gang valves not to block air flow (that is bad for the pump, I'd imagine) but to bleed off some of the air. So install one gang valve on the air pipe going to the air stone, and open the valve a little if you need to reduce the flow of bubbles. This way there's no backwards pressure pushing against the air pump, which to my thinking should help it last longer. Do also remember that airstones create resistance, so an air pump that seems strong enough when you hold the plastic tube underwater may suddenly become inadequate once you add the airstone! I'm not sure it affects the performance much, but placing the air pump above the waterline is good advice as it prevents back-flows of water into the pump (and therefore out of the aquarium) should the pump fail. You can buy little check valves that will prevent back-flow if you can't position the air pump above the tank. Do also check the filter on the air pump: these get clogged very quickly, especially if the tank is in a corner where dust and debris are easily overlooked.
Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?    8/9/13
I had a check valve and it was set high.
<An adjustable check valve? Have never encountered such. Do you mean it was installed backward?>
I think the pump just got messed up.... I debugged that it will blow a single stone so that means the pressure is just lower.  I probably messed it up.
<Ok>
Have you ever looked inside a Fluval?
<Yes>
 Is the small black plunger part the bag....it's thick...like a real plunger rubber.
<Yes; the diaphragm...>
  I'm wondering if the bag is under that.  There's a bar across and I'd need to unscrew it to find out.  I suspect most people buy a new one as all the YouTube's I've found show older styles of pumps, not Fluval.
Have you ever used Fusion brand?  It sounded quiet in the store while cheaper store brands rattled and hummed.  Thanks Neale.
<Most all small/hobbyist air pumps are about the same; some with more diaphragms, different quality "one way" flap valves; some with novel sound insulating.... Bob Fenner>
RE: Gang valve for sharing an air pump with bubblers?    8/9/13
I put them on smaller pump and they all worked.  Figured out I can run one stone on it so I think the bag is old, maybe I need to replace it.  For now I'll run one stone off it till I can fix it or buy a larger one as Neale suggested I may need to do.  May have been too much even though the manufacturer says it's doable, maybe they only mean 5 small air stones and some of mine were larger.
I'll check your article.  Thanks Bob.
<Easiest to buy a single good pump (ideally with one outlet if simplicity is important, because you need to balance the load on each air line if there are two outputs on an air pump), and then bleed off what air you don't need as/when required. Eheim make very good value, reliable air pumps. Most air pumps these days use rubber diaphragms that wear out, and often need replacing annually, and there's normally an filter over the air inlet on the pump that needs replacing as/when required. Otherwise, air pumps are exceedingly simple devices and shouldn't cause you any great problems. Cheers, Neale.>
 RE: Gang valve for sharing an air pump with bubblers?
I used one less of the valves and would release pressure every 2 weeks to a
month, but maybe I need to do it more frequently.  When I did it sometimes
I couldn't get them all running again and so I'd procrastinate.  I was
probably overloading it and under maintaining it.  I probably need a bigger
pump as some of the air stones are larger types.
<You need to get the pressure balanced constantly, and should never have an
air pump working so hard it needs pressure released every few days (though
I have no idea what this actually means to be honest). Get the right pump
for the job, one that's working within its abilities so far as demands are
concerned, and leave it be. Almost zero maintenance devices, apart from
occasional air filter cleaning and annual (?) replacement of the rubber
diaphragm. Cheers, Neale.>
wetwebmedia.com
Subject: RE: Gang valve for sharing an air pump with bubblers?
Bob, is a bubble wall a pump killer? Yeah...I had this pump 8 months, from
your post it sounds like that's a typical life span for the bags. The
bubble wall is new and the pump never ran it, but I'll return it if it's a
bad thing.
<Any pump will wear out faster if there's excessive back-pressure... i.e.,
the air pump is having to work at or beyond its design limit, pushing air
deeper down the aquarium for example, or through many airstones or
ornaments. Given light work, they last years, seriously. I've had air pumps
chugging along for 10 years with minimal maintenance. Sounds to me like
you've either got a poor/duff air pump, or else you're expecting too much
from it. Yes, those bubble walls require a strong pressure, and that means
a strong pump, and the finer the bubbles, the harder the pump has to work.
Ditto, the deeper the bubbler, the harder it is for the pump to push air
down into the bottom of the tank. Review, and act accordingly, choosing an
appropriate air pump for your aquarium. Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Bob,
<Jill>
The air pump was set high up.  Sorry, in his reply, Neale told me to use a
check valve and to put the air pump up higher than water level,
<These are useful statements. I'll leave it to Neale to deal w/ your queries. B>
and I was just clarifying that I had done those things when I originally
set it up and it was working.
If the diaphragm isn't stretched or damaged, does this mean that I just have
stones that are more than it could handle?  Or could it have a small hole
that I'm not seeing?
My new bubblers are 3 log styled ones and a round coffee warmer size
one and a bubble wall.  Maybe I need a pump for a 100 gallon to run that many.
But still....   it was running one log style and the coffee warmer size and an airstone prior to the time I stopped doing that and would only run one-
the coffee warmer one was the one that was working.  I had it on a plastic
4 valve and would use the 4th to release air periodically.
Neale mentioned that a filter could have possibly gone out, is that
different than the diaphragm?  The power box is probably the little box
where Fluval sealed the screws with super glue because they don't want you
to open it... If the filter's in there I'm not sure I can get to it.
Do you have a favorite brand of air pump?  Qualities I appreciate are
QUIET, and if it were fairly simple to do maintenance on that would be nice
too.
I know none are completely quiet but Marina and the PetSmart store brand
are noisy, and unfortunately the plastic piece that you attach the hose to
on a Tetra Whisper broke on me after not having it very long so I don't
trust that brand.  I heard a Fusion in a store and it seemed quiet.  I did
like the Fluval...   I just need to figure out why it lost some pressure
with no visible sign of damage.  Maybe it could be the gang valve but it's
chrome and I could feel a good stream of air through each of the valves.
Jill
Sent from my cell phone using a tiny keyboard, so I'm sorry if there are
typos!
RE: Gang valve for sharing an air pump with bubblers?      8/10/13
Bob, is a bubble wall a pump killer? Yeah...I had this pump 8 months, from
your post it sounds like that's a typical life span for the bags. The
bubble wall is new and the pump never ran it, but I'll return it if it's a
bad thing.
<Any pump will wear out faster if there's excessive back-pressure... i.e.,
the air pump is having to work at or beyond its design limit, pushing air
deeper down the aquarium for example, or through many airstones or
ornaments. Given light work, they last years, seriously. I've had air pumps
chugging along for 10 years with minimal maintenance. Sounds to me like
you've either got a poor/duff air pump, or else you're expecting too much
from it. Yes, those bubble walls require a strong pressure, and that means
a strong pump, and the finer the bubbles, the harder the pump has to work.
Ditto, the deeper the bubbler, the harder it is for the pump to push air
down into the bottom of the tank. Review, and act accordingly, choosing an
appropriate air pump for your aquarium. Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Thanks Neale.
Is it ok to use a t-valve?  I've purchased a 6 slot valve...  and most Of
the larger size larger pumps have two ports as standard, (though maybe if I
shop some more I can find a single port style.)
<If you mean like the Algarde Tee Valve, then I would not personally use
one because when these are closed to limit air flow, they increase pressure
on the air pump. Look for something like the Algarde 2 Way Gang Valve,
which has two outlets, one you connect to your airstone, and the other you
open or close to bleed off air and thereby reduce the flow of bubbles.>
I'll check for Eheim.  I haven't seen it in the stores, but the chain store
selection is dismal.  I'll probably end up ordering a pump online!
Jill
<Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Neale,
What size would you recommend for these stones, if I were to consolidate to
one large pump rather than running more than one per set of stones?  Try
not to laugh.  Total stones I have that would be nice to consolidate pumps
for:
1- six inch long bubble wall in a 30 gallon
<This will need a big air pump, probably the largest in whatever range you
look at, or at least in the upper half of the range.>
2- 4 inch long log style bubblers, one in a 3 gallon and one in a 5 gallon
<Ditto. These air bubble curtain things need a fair amount of air to work
as advertised.>
1- coffee cup size warmer size bubble plate in a 5 gallon
<Ditto.>
And 2 air stones run through little plastic container pumps with a mini
filter in them in two 3 gallons
<A small air pump, I wouldn't get the absolute smallest, but something in
the bottom half of the range will be fine.>
And 2 more single air stones one in a 3 gallon and one in a 10 gallon?
<Ditto.>
Or maybe I could divide between 2 larger pumps!!!!  lol
<Likely so, but obviously you would need a big pump for the two heavy duty
demands, and a not-too-small pump for too minor demands. Be sure to connect
up equal loads to the outlet from a single-outlet pump: air tends to flow
down the line of least resistance, which will be the minor load, and if you
have one minor load and one heavy load on an air pump, you'll get less good
performance. This rule is mandatory if you connect two loads to two
different outlets on the same pump as dissimilar loads on each outlet will
wear out the pump faster.>
The tanks are doing well, they all have a lot of plants that are
flourishing, and the 3 and 5 gallons have one small fish each, the 10
gallon houses cherry shrimp.
<Real good.>
I seem to do well with planted nano setups, and the 30 gallon has a lime
green Endler's colony which has been headache free so far.  It has a filter
for a 45 gallon so maybe I don't need a bubble wall, it bubbles and they
love to play in the current which is to the front of the tank while they
seemed to ignore the prior bubble log I was using before it all went out on
me.
Maybe the current is more natural to them then bubbles.  I got that size
filter as it was on sale for cheaper than the 30 gallon size, and they tend
to multiply so I wanted to make sure they always have excellent
filtration.
Jill
<To be fair I hardly ever use air; there's never a situation where
more/stronger filtration wouldn't do the same job but better, so I tend to
use extra/bigger filters to turn the water over more vigorously. Air pumps
are strictly optional in most situations. Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Bob,
<Jill>
The air pump was set high up.  Sorry, in his reply, Neale told me to use a
check valve and to put the air pump up higher than water level, <These are
useful statements. I'll leave it to Neale to deal w/ your
queries. B>
<<<Thanks Bob!!!>>>
and I was just clarifying that I had done those things when I originally
set it up and it was working. If the diaphragm isn't stretched or damaged,
does this mean that I just have stones that are more than it could handle? 
Or could it have a small hole that I'm not seeing?
<If the air pump is working, you should get a flow of air from the outlet
that you can feel with your hand. If you can't, then yes, the diaphragm may
be broken. Cheap fix. Likewise some air pumps need a little maintenance now
and again; consult the documentation that came with yours. If the air pump
is working fine, and even a poky little filter should be able to blow
bubbles down 30 cm/12 inches if you stick some air line into a bucket of
water, then something else may be amiss. Yes, you can overload air pumps,
forcing the pump to try to lift air against too much water, and if that
happens, the pump won't seem to do anything. Try a bigger pump, and if the
ornament works now, then obviously the previous pump was too small.
Alternatively, remove the ornament, and see if bubbles come out; if they
do, then again, the ornament was too much for your pump. Remember, every
time you add an ornament, use a bigger ornament, use a finer airstone, or
put the ornament or airstone deeper down the water column, the air pump has
to work harder. It has an absolute limit beyond which it can't move air,
and once you pass that limit, you'll see no air bubbles even though the
pump sounds like it is chuffing away. The very small pumps sold
inexpensively tend to be for very small tanks, sub-10 gallons, with one
airstone or sponge filter under 20 cm/8 inches of water.>
My new bubblers are 3 log styled ones and a round coffee warmer size
one and a bubble wall.  Maybe I need a pump for a 100 gallon to run that
many.
But still....   it was running one log style and the coffee warmer size and
an airstone prior to the time I stopped doing that and would only run
one-the coffee warmer one was the one that was working.  I had it on a
plastic 4 valve and would use the 4th to release air periodically.
<I still don't get this. You should not need to "periodically" release anything; if your air pump works fine for a while, then starts rattling or something else is going wrong -- then you haven't set it up right. Review, and act accordingly>
Neale mentioned that a filter could have possibly gone out,
<Little patch of sponge or cotton, usually circular, underneath the air pump. Air is sucked in here, and blown out through the outlets. Refer to the manufacturer or the documentation that came with your air pump.>
is that different than the diaphragm?  The power box is probably the little box where Fluval sealed the screws with super glue because they don't want you to open it... If the filter's in there I'm not sure I can get to it.
Do you have a favorite brand of air pump?  Qualities I appreciate are QUIET, and if it were fairly simple to do maintenance on that would be nice too.
<The Eheim pumps are well-designed and good value, like most/all of their
products.>
I know none are completely quiet but Marina and the PetSmart store brand are noisy, and unfortunately the plastic piece that you attach the hose to on a Tetra Whisper broke on me after not having it very long so I don't trust that brand.  I heard a Fusion in a store and it seemed quiet.  I did like the Fluval...   I just need to figure out why it lost some pressure with no visible sign of damage.  Maybe it could be the gang valve but it's chrome and I could feel a good stream of air through each of the valves.
Jill
<I don't believe any aquarium air pump sold today is truly quiet; all rattle and vibrate because of the back-and-forth movement required by the mechanism. Sitting them on soft objects like cloths is often suggested as a silencer, but do remember that these impede the flow of air, causing the pump to overheat, so this cannot be recommended. Have your retailer test the pump out in the store, and choose one that sounds good to you. For what it's worth, I avoid using air pumps in rooms where quiet is important, and prefer to use canister filters to create current instead. Total aside, but a British manufacturer called Medcalf used to make "Hy Flo" air pumps that worked completely differently. They had a rotating wheel and pistons, and were made from solid metal, and were hypnotic to watch as well as virtually silent because they span round rather than rattled back and forth. Sadly they were expensive (metal vs. plastic) and the company collapsed 10, 20 years ago. If you're curious, there's a neat video of one here:
http://www.youtube.com/watch?v=ORo7KQ-mYsM
I dare say these things are still about on eBay, and you might find one fun to try out if you could get one cheaply. Cheers, Neale.>
wetwebmedia.com
Subject: Re: Gang valve for sharing an air pump with bubblers?
Actually, I could see if I could fix the Fluval and also get a larger pump
and try and divide them so the larger would carry more weight....  But the Fluval can probably handle 4 small air stones at least.
Maybe I should return the bubble wall, Bob said those are bad.  The logs are like a bubble wall too though. 
<They do place a big strain on an air-pump, and most fish despise swimming through bubbles, so it becomes an unnecessary barrier in the aquarium.>
I want all of the fish to have a clean and aerated and entertaining ,
that's why I have so many stones, and to help the plants thrive as well.
<Remember, all air stones do is lift water from the bottom of the tank to the top. They DO NOT add any appreciable amount of oxygen. That happens at the surface, and air stones help by getting water from the bottom to the surface. That's all. In every imaginable situation, doing the same thing with a properly sized/installed filter will be better -- not only will it move water from the bottom to the top, it will also remove ammonia and nitrite, plus any silt that makes the water cloudy. Air stones are largely obsolete, so don't spend insane amounts of time/money worrying about them.
Cheers, Neale.>
Re: Gang valve for sharing an air pump with bubblers?
Thank you, Bob.
I appreciate your advice as well.
<Ah, welcome. B>
Re: Gang valve for sharing an air pump with bubblers?
That's helpful, thank you Re: Gang valve for sharing an air pump with bubblers?
Thank you.  It was probably the unbalanced load, as well as too many stones, that wore it out.  Your info has been extremely helpful.  This will help me do a better setup for next time.
<Cool.>
I like the larger filter.  The fish entertain themselves in the flow.  They tend to do that in the late evening especially when I'm off work and relax in that room, I see them swimming without moving forward because they're riding the current.
<Indeed.>
I have trouble with the filter situation in the 5 gallon tanks though.  The small Marina filter killed a smaller fish, it got caught on it's intake and she died.
<Or she died and got sucked in. Post hoc ergo propter hoc isn't always true.>
I put a sword in the other one because she's bigger, and the other is still empty.  I was wondering if a small canister filter would be safer for small fish?
<Depends on the fish and the size of the tank. But an air-powered sponge filter is the ideal for livebearer fry and very small, weakly-swimming species, such as the tiniest tetras, dwarf rasboras, etc.>
I'd seen one online by Lee's Pets.  The tiniest size only uses a bubbler but the next larger uses an airstone inside the filter.  It's old fashioned but possibly less expensive to upkeep.  You put a little carbon, some kind of media stones to colonate bacteria, and filter floss or fluff.  Have you ever used small canister filters, do you think the current would be safe enough for a female Betta or bumblebee goby to live there without getting caught on the filter by the intake?
<Bumblebees do fine even in strong currents; like all gobies, they've evolved to "suck" onto rocks with their pelvic fins. Bettas are trickier.
Some Betta species (the mouthbrooding ones, mostly) come from fast-flowing streams (that's why they don't build bubblenests) but the standard aquarium shop Betta splendens appreciates weak to zero current, so I'd go with an air-powered sponge with them.>
I can't due an undergravel because I have sand and plants, it would be too much hassle.
<Depends on the plants, epiphytes don't care, but yes.>
If I did that I could shut down the two 3 gallons and graduate the sword to a larger tank with a school....and the Betta and goby could have larger quarters.  But I'm not sure there's a filter that would be good enough and not have a fish killing intake.
Though there's also sponge filters.  With a low fish load and plenty of plants, maybe that would work on those two tanks and make sure I keep a careful eye on water quality.
Thanks.
<Cheers, Neale.>
u.
<Most welcome. Neale.>
RE: Gang valve for sharing an air pump with bubblers?
That's cool.  Thanks.  Very helpful.  I see know I had an unbalanced and
overloaded Pump.  It's still able to run one log.
I'm not sure why they say to release air occasionally, but Whisper and Fusion had it in their manuals.
<Makes no sense at all.>
Fusion doesn't have a technical manual with pictures online (at least I couldn't find one on their web page relating to the maintenance issues).  I suspect they hope if you pump fails, you'll  buy another,
<For sure.>
though maybe if I'm able to locate and purchase their maintenance kit it will have paper illustrations in that.
I'll check around for Eheim.  They sound good....and I looked at their web page and was impressed.
<Most folks are; their air pumps are actually very competitively priced (here in the UK, at least).>
Enjoy the rest of your weekend.
It's kind of you to share your expertise.
Jill
<Welcome, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Thanks.
The fish was a small one.  She acted healthy.  She had got stuck on a filter once in the past and then been revived. 
What's amazing is the shrimp were all over that filter, and now the 10 gallon's filter, and they're very tiny.
Thank you.
<Welcome. Do consider using an air-powered sponge where fish are so small/feeble they're at risk of being damaged by the filter. Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
Thanks.
The fish was a small one.  She acted healthy.  She had got stuck on a filter once in the past and then been revived. 
What's amazing is the shrimp were all over that filter, and now the 10 gallon's filter, and they're very tiny.
Thank you.
<Welcome. Do consider using an air-powered sponge where fish are so small/feeble they're at risk of being damaged by the filter. Cheers, Neale.>
RE: Gang valve for sharing an air pump with bubblers?
I will.
<Real good. Neale.>
RE: Gang valve for sharing an air pump with bubblers?    8/12/13
Oh darn.  Eheim air pumps are not available in USA at this time. Oh well.
I'll probably go with Fusion or another larger Fluval.
<Sounds like it. Cheers, Neale.>

Aeration for 1 gallon of water    7/15/13
what aerator cfm rate would you recommend for 1 gallon of water?
0.01, 2, 100? Please help me determine which
Thank you.
<... important factors must be added here. What depth one is pumping to, what resistance (gear) is in use. Go fish. B>

Refugium and aeration 4/27/13
Hello crew!
<Josh>
First time writer, long time reader. Great website! I have a 125 gallon long aquarium, heavily planted with co2 system, 35 gallon refugium fed from CPR overflow box and a Fluval fx 5 canister. I currently have a silly volcano in the center (my girlfriends only request) pushing out these huge bubbles that agitate the surface. My question is this- Will the refugium with overflow box cause enough aeration below the tank to keep oxygen levels adequate or must I have an air source in addition? I really want to eliminate the enormous volcanic bubbles. Also, I have the return from the Fluval pointed up to create a good amount of surface movement. Current stock load is about 20 tetras, 6-8 Cory's, 4 bushy nose Pleco and 8 discus in transit. Please help! Thank you in advance for your time and consideration.
-Josh-
<I think you likely have enough surface agitation with the overflow unless you live in a very hot climate, but do be prepared to act if the fish show signs of oxygen deprivation. You might consider replacing the volcano with a sponge filter. Personally, I love sponge filters because you get surface agitation and you get additional mechanical and biological filtration.
Clean water is important for the discus and Plecos are somewhat messy.- Rick>