Purpose Of Air Stones | Air Pumps Forum (2023)

What are the purpose of air stones and when should one use it? I've been reading here about them.

Thnx.

The increase dissolved oxygen, and disrupt surface biofilm.

Some people like the effect of the bubbles rising in the aquarium.

They also inhibit capnophilic bacteria to an extent.

In my experience, if a 10 Gal tank doesn't have an air stone fish will gasp for air at the top.
It all depends on what fish, how many, the size.. there are many variable that play a factor.
It is better to be safe than sorry. Not having enough dissolved oxygen in the water can make your fish gasp at the top which in turn can lead to Swim Bladder disease and all sorts of other health issues.
You won't be able to over saturate the water with oxygen in a normal aquarium setup.

An air stone will also play a huge role in preventing a bio-film as mentioned above.

I personally do not like the look of an air stone or the bubbles and am currently working on building an external aerating canister with an automatic air release valve so that water returned from my canister filter is then aerated and contains dissolved oxygen before being returned to the aquarium.

If you have enough plants even in a small tank with little agitation, you still should not be having oxygen issues unless you have massively overstocked. I do have an airstone to create surface agitation in a nano tank that houses Asian Stone Catfish as they notoriously need highly oxygenated water and a strong filter or powerhead cannot be used in such a small tank.

Edit: I've also had one in a 10 gallon but removed because it did not seem to do anything. You can actually use them with a tube to hatch shrimp eggs if your berried shrimp dies (there are youtube videos of this, very easy to DIY).

What are the purpose of air stones and when should one use it? I've been reading here about them.

Thnx.

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Air stones move water. Moving water help create oxygen. The Air stone produces very little to no oxygen inside the water.

I use them more in the summer. It's always 100* at least, and 110* isn't uncommon, so my tanks run warm even with AC and extra tank fans.

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Whoa, do you run your aquarium outside in summer Kjeldsen? Were are you located? I'm here in Houston, and 110 is uncommon, but 100 is not. And I would love to set up some tanks outside, but I am worried about keeping them cool. What all do you use, and how cool does it get your tank vis-a-vis the outside air? And, the airstones makes them cooler than vis-a-vis using an air pump but no airstone? Or vis-a-vis not using an air pump at all? Very interesting! Thanks!

Air stones move water. Moving water help create oxygen. The Air stone produces very little to no oxygen inside the water.

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But, apart from their water moving ability, don't they also increase dissolved oxygen in the water because they change each big bubble that would otherwise come out of the air tube into many much smaller bubbles, with a combined surface area that is much larger? I always thought that was a part of how they worked, anyways.

Thanks!

But, apart from their water moving ability, don't they also increase dissolved oxygen in the water because they change each big bubble that would otherwise come out of the air tube into many much smaller bubbles, with a combined surface area that is much larger? I always thought that was a part of how they worked, anyways.

Thanks!

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Yes they do.

Whoa, do you run your aquarium outside in summer Kjeldsen? Were are you located? I'm here in Houston, and 110 is uncommon, but 100 is not. And I would love to set up some tanks outside, but I am worried about keeping them cool. What all do you use, and how cool does it get your tank vis-a-vis the outside air? And, the airstones makes them cooler than vis-a-vis using an air pump but no airstone? Or vis-a-vis not using an air pump at all? Very interesting! Thanks!

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I'm in central California, but it may as well be Death Valley. The other day it was 112* and my AC unit died, yesterday it cooled down to 109* and right now it's 100* before noon. So far I've managed by keeping the lights off, fans blowing, and extra water changes. Plus I got a portable swamp cooler that helps a little. I don't think the airstones cool the water any, but they help keep the warm water oxygenated. The fish are holding up better than I am. lol

Thanks Kjeldsen! OK, it sounds like in those temps you have to do water changes to keep the water cool enough so they don't die, I might hold off a bit on setting up some aquariums outside in the 100 plus Houston heat.

Thanks!

Air stones move water. Moving water help create oxygen. The Air stone produces very little to no oxygen inside the water.

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This is a very common myth which was disproven nearly 3 decades ago, if not earlier:

Wilhelms 1992

You won't be able to determine if oxygen levels are adequate without measuring. Levels are way too low by the time you notice fish gasping. Somewhat low levels won't be obvious by observing the fish but they'll grow slower and be more susceptible to disease.

This is a very common myth which was disproven nearly 3 decades ago, if not earlier:

Wilhelms 1992

You won't be able to determine if oxygen levels are adequate without measuring. Levels are way too low by the time you notice fish gasping. Somewhat low levels won't be obvious by observing the fish but they'll grow slower and be more susceptible to disease.

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Learn something new every day. Guess I've been a parrot lately

This is a very common myth which was disproven nearly 3 decades ago, if not earlier:

You won't be able to determine if oxygen levels are adequate without measuring. Levels are way too low by the time you notice fish gasping. Somewhat low levels won't be obvious by observing the fish but they'll grow slower and be more susceptible to disease.

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So wait a second, if "The results indicated that about one-third of the oxygen [absorbed] was due to surface exchange", isn't he correct at least 1/3rd of the way lol? I.E. even taking away the absorption of oxygen from the bubbles into the water completely there was still some material (here, 1/3 of the total) oxygen absorbed into the water? Clearly, the minority of the total, but not an insignificant amount. And that was a meter down, sounds like they are saying in a typical aquarium that is shallower this % might be more? That actually suprises me a bit, I would have thought the VAST majority was the O2 leaking into the water directly from the bubbles.

Oh, the whole "air stone produces very little oxygen inside the water" is dead wrong UNLESS he was trying to say the air stone itself produces no oxygen inside the water *vis-avis* just having an air tube in the water without an air stone, and that is a stretch to interpret it that way, even if true (which seems a bit unlikely).

So wait a second, if "The results indicated that about one-third of the oxygen [absorbed] was due to surface exchange", isn't he correct at least 1/3rd of the way lol? I.E. even taking away the absorption of oxygen from the bubbles into the water completely there was still some material (here, 1/3 of the total) oxygen absorbed into the water? Clearly, the minority of the total, but not an insignificant amount. And that was a meter down, sounds like they are saying in a typical aquarium that is shallower this % might be more? That actually suprises me a bit, I would have thought the VAST majority was the O2 leaking into the water directly from the bubbles.

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No, the myth that is repeated ad nauseam is that bubbles contribute little, if any, to oxygen transfer and that it's nearly all from surface agitation.

The tank was 1.3 by 2.6 meters wide and 1.1 meters deep. I think that's a reasonable area vs. depth ratio not too different from aquariums.

There are a few other studies that come up with similar results.

A related question is whether surface agitation or bubble aeration is superior since people talk about surface agitation as if it's the only thing that matters. There are studies comparing oxygen transferred per energy consumed. Bubble aeration is several times more efficient even when compared to surface aeration that's much more vigorous than what you see in aquariums.

No, the myth that is repeated ad nauseam is that bubbles contribute little, if any, to oxygen transfer and that it's nearly all from surface agitation.

The tank was 1.3 by 2.6 meters wide and 1.1 meters deep. I think that's a reasonable area vs. depth ratio not too different from aquariums.

There are a few other studies that come up with similar results.

A related question is whether surface agitation or bubble aeration is superior since people talk about surface agitation as if it's the only thing that matters. There are studies comparing oxygen transferred per energy consumed. Bubble aeration is several times more efficient even when compared to surface aeration that's much more vigorous than what you see in aquariums.

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Makes me wonder if an airstone would offgas co2 more quickly or if surface exchange would fare better.

No, the myth that is repeated ad nauseam is that bubbles contribute little, if any, to oxygen transfer and that it's nearly all from surface agitation.

The tank was 1.3 by 2.6 meters wide and 1.1 meters deep. I think that's a reasonable area vs. depth ratio not too different from aquariums.

There are a few other studies that come up with similar results.

A related question is whether surface agitation or bubble aeration is superior since people talk about surface agitation as if it's the only thing that matters. There are studies comparing oxygen transferred per energy consumed. Bubble aeration is several times more efficient even when compared to surface aeration that's much more vigorous than what you see in aquariums.

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That makes sense AvalancheDave. On that last part, if you accept that (i) bubbles in the water generally diffuse more air into the water than the air over the water, and (ii) air pumps are generally more efficient than water pumps (per ml of air versus ml of water), that would seem to almost have to be the case I would guess.

No, the myth that is repeated ad nauseam is that bubbles contribute little, if any, to oxygen transfer and that it's nearly all from surface agitation.

The tank was 1.3 by 2.6 meters wide and 1.1 meters deep. I think that's a reasonable area vs. depth ratio not too different from aquariums.

There are a few other studies that come up with similar results.

A related question is whether surface agitation or bubble aeration is superior since people talk about surface agitation as if it's the only thing that matters. There are studies comparing oxygen transferred per energy consumed. Bubble aeration is several times more efficient even when compared to surface aeration that's much more vigorous than what you see in aquariums.

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The hydroponic farming community has done a lot of research on bubbles in water...airstones vs venturis etc.
I agree there a preponderance of actual real data published that is easily accesible...but the cliche of surface agitation lives on.

Makes me wonder if an airstone would offgas co2 more quickly or if surface exchange would fare better.

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I think it would but I'm not 100% sure. It's just oxygen diffusing from high to low concentrations so CO2 would probably diffuse from high to low as well.

That makes sense AvalancheDave. On that last part, if you accept that (i) bubbles in the water generally diffuse more air into the water than the air over the water, and (ii) air pumps are generally more efficient than water pumps (per ml of air versus ml of water), that would seem to almost have to be the case I would guess.

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Someone on another forum pointed out that it takes less energy to pump air than water so maybe that's it.

The hydroponic farming community has done a lot of research on bubbles in water...airstones vs venturis etc.
I agree there a preponderance of actual real data published that is easily accesible...but the cliche of surface agitation lives on.

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I actually had trouble finding scientific research. I made a few half-hearted attempts over the years but the search terms were tricky. Once I found one article they cited each other so I was then able to find more.