Air pump help

[Matt Tx]

I have a 45G tall aquarium which has been up and running for approximatley 7 months. I am running a cascade 700 canister filter and a rio 800 powerhead and a air pump with attacged bubble bar. I have 40# live rock and a 3 to 4" sand bed. Livestock includes yellow tang, 1 percula clown, 2 Green chromis, and a striped damsel, 1 flame scallop, 1 leather, 1 sebea anenome, and some zoos and button poloyps and various crabs and snails.

My question is i added the air pump after some research on the internet about raising you PH since the addition my ph has remained at 8.4 my LFS said that I should remove the air pump because i run the risk of over oxygenating the water and damaging the fishes swim bladders. Is this correct should i remove the air pump and struggle with trying to keep my ph up using buffers if so what type.

Thanks in advance for your responses. Ps I know i should not have bought the tall tank but space was an issue.

[lcstorc]

Most people don't run an air pump with a reef tank. I have never asked why though. I know the co2 level in the water does change the ph but unless there is high co2 we generally adjust with buffers.
Check out the Chemistry forum for lots of great links and info on reef chemistry.

[TurboSnail8898]

Dude, find a new LFS, the one you are going to apparently has no idea what they're talking about. pH should remain stable and within range of natural seawater if your alkalinity/calcium are maintained at appropriate levels. If you don't have coral then regular water changes should replace the calcium that is used by coralline growth. Most people don't use air in their reef tanks because it can cause increased algae growth, at least thats what I've heard.

[Octoman]

As CO2 levels increase in a tank, the pH decreases (because of an increase in Carbonic Acid). This can be a result of inadequate aeration - there are several ways to solve this. 1. - Most of us have skimmers which provide plenty of aeration. 2. - Direct powerheads at the surface of the tank to create agitation and more air exchange at the surface. 3. - install an airstone (like you did) in the tank or sump.

However, in many cases high CO2 in the tank is a result of high ambient CO2 in the home. Houses are sealed up tight these days to save energy and CO2 can be very high indoors. If this is the case, no amount of aeration will help unless the air comes from outside the home. Some people have installed home air exchange units to help with indoor CO2 levels (high levels are not so good for you either...).

As far as gas bubble goes, the LFS is wrong. I have dealt with gas bubble disease in fish before, to create this condition, you need a strong pump that is sucking air and water in order to over-oxygenate the water. The pump drives the oxygen into the water at levels that are excessive, but in the case of an air stone or bubbler, this isn't going to happen. Even a needle-wheel skimmer is not powerful enough to create this condition, otherwise a lot of us would be in trouble.

[glampka]

I would dump the air pump. You don't need it if you have adequate circulation in the tank & don't have a glass top. Additionally, the bubbles breaking cause all sorts of salt creep which is a real pain to keep clean.

[Woodstock]

Originally Posted by Octoman

As CO2 levels increase in a tank, the pH decreases (because of an increase in Carbonic Acid). This can be a result of inadequate aeration - there are several ways to solve this. 1. - Most of us have skimmers which provide plenty of aeration. 2. - Direct powerheads at the surface of the tank to create agitation and more air exchange at the surface. 3. - install an airstone (like you did) in the tank or sump.

However, in many cases high CO2 in the tank is a result of high ambient CO2 in the home. Houses are sealed up tight these days to save energy and CO2 can be very high indoors. If this is the case, no amount of aeration will help unless the air comes from outside the home. Some people have installed home air exchange units to help with indoor CO2 levels (high levels are not so good for you either...).

As far as gas bubble goes, the LFS is wrong. I have dealt with gas bubble disease in fish before, to create this condition, you need a strong pump that is sucking air and water in order to over-oxygenate the water. The pump drives the oxygen into the water at levels that are excessive, but in the case of an air stone or bubbler, this isn't going to happen. Even a needle-wheel skimmer is not powerful enough to create this condition, otherwise a lot of us would be in trouble.

Ditto to the above post!

With that said, the airwand is not hurting anything and is only helping. If you do not mind the saltcreep it creates (as the bubbles pop at the surface) keep it. I like the look of cascading bubbles.

When I had a large bioload with all my fishes in the hospital tank for 8-10weeks...twice, I used a large airstone to aid in gas exchange (absorbs o2 and blows out co2).
Bubble wands are also used when rearing fish larvae for the same reasons.

[TurboSnail8898]

Octoman- How did you manage to supersaturate your water?

[Octoman]

This was 11 years ago on a large LFS system. During the night, something caused the sump (6 feet deep, 4 feet wide) to get low on water. The pump (I think it was a 2 hp pump) started sucking air and water. All of the larger fish on the system died, many of the smaller ones made it. You could see the gas bubbles in the fins of the larger fish. It was a very sad day...

[TurboSnail8898]

Wow, I was wondering what type of pump would be required to do that.