I've read in a few places now suggesting that air bubbles don't dissolve fast enough before it hits surface to add oxygen. But in fact it is the broken surface tension that provides the oxygen. Is this true? Would a cheap/old powerhead pump pointed up at the surface provide a lot more oxygen?
Do air stones REALLY provide oxygen to the tank?
- Thread starter unseenone00
- Start date
Yes, it's true, and yes a powerhead will suffice. But so will any hang-on-back filter that disturbs the surface.
oxygen will dissolve from the bubble on a molecular level. it may be insignificant but still could amount to something over a while, it also creates surface disruption that disolves oxygen as well.
I think the confusion is that we're pumping air into the water so then it must dissolve. The fact is, as stated, the oxygen in the air is trapped in the bubble. When the bubble breaks at the surface CO2 is released into the air and O2 is absorbed in the water in a gas exchange. I don't think water moving quietly on the surface provides quite as much exchange as bursting bubbles or a waterfall, but without sophisticated equipment, I'm not sure how we'd measure it.
Air stones do provide active aeration. Aeration will occur at ANY air-water surface. The oxygen doesn't stop and think 'wait, this isn't the tank's surface, I have to wait'. It diffuses, which is almost instantaneous.
An air pump is always a good idea. Even if you just want flow they are a great option. The 220 with a 22" pacu and 20" catfish at the shop I was running got much more flow from the two air stones than from the FX5.
Small bubbles create more surface area per volume of air, but large bubbles create more flow. Either way you get better aeration.
An air pump is always a good idea. Even if you just want flow they are a great option. The 220 with a 22" pacu and 20" catfish at the shop I was running got much more flow from the two air stones than from the FX5.
Small bubbles create more surface area per volume of air, but large bubbles create more flow. Either way you get better aeration.
Bubbles circulating in the tank pushing water from the bottom towards the top, are not as effective as powerheads swirling the surface of the tank....this is why undergravel filters function much more efficiently with powerheads than they do with airstones.
Are you talking about flow or aeration?
If you are talking about flow that depends on the pump used. A strong enough air pump will exceed the flow created by a pump. Like I said, two air stones in a 220 created multiple times the amount of flow as the FX5 did.
If you are talking about aeration that is debated. Other industries rely on bubble aeration, not surface aeration. For some reason it just can't catch on in the aquarium hobby, but sewage treatment and real aquaculture (commercial farms, not hobbyists) use bubble aeration for active aeration. In this hobby everyone is told the myth that bubbles do nothing and then just repeat it over and over.
If you are talking about flow that depends on the pump used. A strong enough air pump will exceed the flow created by a pump. Like I said, two air stones in a 220 created multiple times the amount of flow as the FX5 did.
If you are talking about aeration that is debated. Other industries rely on bubble aeration, not surface aeration. For some reason it just can't catch on in the aquarium hobby, but sewage treatment and real aquaculture (commercial farms, not hobbyists) use bubble aeration for active aeration. In this hobby everyone is told the myth that bubbles do nothing and then just repeat it over and over.
It DID catch on in the aquarium hobby...if you remember...
Salt, carbon and airstones were all mandatory back then. Now we know that freshwater fish don't need salt, carbon is entirely optional, and airstones have been replaced with less noisy, messy and disposable means of providing circulation and increasing gas exchange:
http://saltaquarium.about.com/cs/waterquality/a/aa122997air.htm
With all due respect, I don't think most people would agree that two airstones provide more flow than 900 gph.
air stones, to some people, make the tank more aesthetically pleasing. I tend to agree. There's something relaxing about it.