How O2 is enough O2?

**Cliff** · 03-02-2010, 12:47 AM

Up until a 4 months ago I always had a under gravel air filter / cleaner which added O2 in the water. I got rid of the under gravel filter / cleaner once I started to read about the problems that can come with them. Up until then, I always had that under gravel filter in my 55 gallon tank.

I have now added a single 4” are stone hooked up to a single air pump.

How do you determine if you are putting enough air into the water ? I can’t believe I’ve never even ask this question before !

Oh ya, more tank details:
55 gallon
Fluval 405 filter
Lots of plants
Lower light levels
PH 7.6, ammo 0 nitrites 0, nitrate between 5 to 10

**rich311k** · 03-02-2010, 12:55 AM

If your fish are not gasping or hovering around the surface they have enough O2. I do not use airstones in any of my tanks. The filter provides adequate circulation. You will know if they are suffering, it is sad to see a fish that is diprived of O2 gasping at the surface.

**gm72** · 03-02-2010, 01:14 AM

By adding an air stone to the tank you are actually making it harder on the plants as they need CO2 to thrive. An air stone is not necessary in the vast majority of tanks, especially those with plants.

**Cliff** · 03-02-2010, 03:01 AM

Thanks for the replys

Even with the plants I was worried about a lack of O2. My fish have never shown signs of suffering from a lack of O2. They never struggle to breath and they pretty much stay in the bottom half of the tank, unless it’s feeding time. Ever since I switched to a canister filter, I’m having some difficulty judging the other impacts on the tank as apposed to the HOB filters I’ve used in the past. As I’ve seen a lot of pics of tanks with air stones in then, I started to think I needed one to.

I’m going to turn off the air stone for now. If I see any changed behaviour in my fish that would suggest they need more O2, I can turn it back on

Thanks for the advice.

**Dacotah7** · 03-02-2010, 05:24 AM

Hey Cliff,

I'll bet you will be ok without the air pump.

I don't own an air pump. In my 125g I normally run 2 Fluval 404's, but for the last two weeks one has been off because it was leaking. In the past my tank has been stocked 3 times as heavy as it currently is and one 404 handled it just fine. I do ensure the return water discharging into the tank causes waves and bubbles at the surface. I do this by not filling the tank to the very top. The surface turbulence also eliminates most surface layer gunk on top of the water.

Ditto the comment about fish gulping for air at the surface.