Myths about using air stone?

[gveng]

i've been keeping tropical fish for the last 3 years and i've always used an air stone and air pump... always!!

now i find this site, and people keep saying that if you have enough water surface movement you don't need to use an air stone.

so, my question is... what is enough surface movement? is their a guideline to go by?

or is it more of a "if the fish appear to be fine, everything is ok"

 

[Laticauda]

I have two heavily planted tanks, with very low flow out of the filters. There is not much surface movement, but the plants do a pretty good job of oxygenating the water, and at night, there is enough surface movement to sustain the fish.

However, in my high stocked, low planted tanks, I have to have air stones, because the fish stay near the surface (where the O2 levels are higher) and that tells me the water's O2 is not enough/being used up too fast and the water needs more oxygen in it.

It really depends on a lot of factors.

 

[gveng]

so lets say unplanted 20g with a hob filter and only 2 fish. lol

 

[Dr_Shakalu]

I think that as long as your fish are doing well, you shouldn't have to worry about an air stone. I have a 168 gallon glass tank and have 2 to air stones on each end of the tank but I think that even withtout the air stones, my fish would be okay.

 

[Toby_H]

By design, HOB filters create more surface agitation than any sized air stone will...

 

[dr_sudz]

as long as the surface is rippling you should be ok you might need a power head or two if you don't think your getting enough if you don't want to do the air stones.

 

[Laticauda]

That sounds fine to me. Another reason I've used air stones, is to help with water circulation and to prevent dead spots. A 20 gallon is rather small, and if your water level is low enough to cause considerable surface agitation, I don't think you would need any additional aeration.

Wait, is it a 20 long or a 20 tall? I was thinking 20 tall, for a 20 long, you may want a powerhead or airstone to help with circulation, to get the water from one end of the tank over to the other end where the filter's intake is. But that's moving away from O2 concentration and talking about water quality.

 

[gveng]

it's a 20g breeder, it's more long then tall.

 

[scriving]

the thing is oxygen can only enter water through surface agitation and usally an air stone is creating the most but your hob filters are creating more than your air stone most likely espically if you drop the water level so your fish will have plenty of oxygen but air stones look nice so if you have good luck with them why stop

 

[knifegill]

Remember that plants remove oxygen from the water at night. This only becomes a problem in tanks that have a large amount of plants and are also stocked heavily. So check your fish when you get up at random in the night and make sure they aren't gasping for air when you're sleeping soundly. But it is true that surface movement doesn't need to be extreme as long as you're not overstocked.