How Much Aeration is Enough?

Considering a normal tank, how much aeration is enough? With a HOB and a waterfall effect breaking the surface, and an air pump with a bubbler, how much would be enough?

I know the HOB alone can provide enough aeration, but I never run a tank without an airstone. I want a backup.

Basically, the difference is an airstone with a gentle flow, or one with a medium flow, or one that is full-blast with bubbles. If the airstone alone had to keep the tank aerated, what would be the recommended minimum amount of air flow?

I like a good flow of bubbles, but for visual effect and to minimize water flow for smaller fish/possible stress from the amount of bubbles, what would be the lowest flow rate that would still aerate the tank and keep the fish alive? (Looking for generals here, doesn't have to be in air pump sizes or GPH.) I would probably go above the minimum, just wanted a range.

 

Air stones are more for breaking surface tension than giving your fish air. as long as you've got some surface agitation I don't think there's anything to worry about.

 

I know how airstones work, my point was how much aeration was required to sufficiently break the surface tension and allow enough oxygen to be absorbed.

I have a Hydor H2Show volcano. It's puts out a ton of microbubbles, and it's adjustable from a slow flow to a giant stream of big bubbles. It looks better with the smaller, slower bubbles. But at it's lowest, it doesn't look like there is much surface tension being broken. My fish don't seemed bothered by the giant flow of bubbles, but I would prefer to reduce it to provide a better look, decrease water flow in that area, minimize any possible stress from it, and quiet it down (on medium-high, high it sounds like Alka-Seltzer in the water.)

That's why I asked.

 

I have both HOB and the air stone in my tank. At first I thought you needed air stones because fish needed...air?

I have it as a back up because my HOB has busted twice on me, so I have one there for good measure.

I think as long as you have a HOB breaking water surface you should be find with what ever setting you want.

But if you fill the tank all the way up to the point the filter isn't making that water fall noise than I would increase bubble size just as insurance.

 

I have both HOB and the air stone in my tank. At first I thought you needed air stones because fish needed...air?

I have it as a back up because my HOB has busted twice on me, so I have one there for good measure.

It used to be thought that the oxygen was absorbed into the water as the bubbles rose, but it was found out that there is not enough contact time for the bubbles for enough oxygen to be absorbed.

So it turned out it was the surface tension being broken by the bubbles that did it.

I think as long as you have a HOB breaking water surface you should be find with what ever setting you want.

But if you fill the tank all the way up to the point the filter isn't making that water fall noise than I would increase bubble size just as insurance.

That's the problem. I have my waterline close to if not up to the inner rI'm edge, and my water return on my old filter was actually underwater (it had a lower return.)

With the AquaClear 20, it produces a waterfall effect, but not a ton of one from the normal water level. (It's very quiet, regardless. It's clearly breaking the water surface, and it's about an inch or so above the water level, but it's quiet.) I have my aeration feature cranked to max just in case, but wanted to lower it and wanted to know an acceptable level of aeration.

 

Breaking surface tension is one way to oxygenate, but the more common way it happens with an airstone is through agitation. Agitation increases the surface area of water-air contact, and thereby increases O2 transfer.

One airstone is enough for most average-sized aquariums. If your filter agitates the water enough (even without breaking surface cohesion) it will also do. I never used airstones very often in my tanks because I disliked the noise he air pump made, and have never had an O2 issue because the filter always created enough agitation.

Good luck!

 

Well, perhaps you could a small shI'm beneath your HOB to allow for more of a waterfall effect, and therefore break up water tension. But really, as to how strongly an airstone should flow is up to you and what you think looks good. H Severum is quite right, I think in pointing out that the point of an airstone is to provide surface turbulence, not just to turn over water, but also to allow the breakup of any surface film that might impede gas exchange.
I'm quite sure that he wasn't trying to tell just how an air stone works.--rick, with due regards to both

 

Breaking surface tension is one way to oxygenate, but the more common way it happens with an airstone is through agitation. Agitation increases the surface area of water-air contact, and thereby increases O2 transfer.

One airstone is enough for most average-sized aquariums. If your filter agitates the water enough (even without breaking surface cohesion) it will also do. I never used airstones very often in my tanks because I disliked the noise he air pump made, and have never had an O2 issue because the filter always created enough agitation.

Good luck!

Unless it's on low, or clogged with brown algae (I made a separate thread for that) it pumps out a ton of bubbles, so I think it's set for surface agitation.

Thanks.

Well, perhaps you could a small shI'm beneath your HOB to allow for more of a waterfall effect, and therefore break up water tension. But really, as to how strongly an airstone should flow is up to you and what you think looks good. H Severum is quite right, I think in pointing out that the point of an airstone is to provide surface turbulence, not just to turn over water, but also to allow the breakup of any surface film that might impede gas exchange.
I'm quite sure that he wasn't trying to tell just how an air stone works.--rick, with due regards to both

I am happy with the distance between my filter's output and the water level. It was the old filter which had the output underwater.

The filter makes a waterfall effect, it's just not a drop of several inches like I have seen on some people's tanks.

It's just a just to be sure thing.

Just for the record, this is the aeration feature. I posted it in the thread about brown algae clogging it.

That's it on about medium-high. I have it set on high right now.

I want it a little lower than that.

 

I haven't had an airstone in my tanks for years. I would use powerheads and a canister filter to create movement in the water, but I had nothing breaking the surface.

I just recently added an airstone to my tank because I am trying live plants and I wanted to have the water turning over so my nutrient additives are mixing in there good.