Importance of aquarium aeration

eon aquatics

Aimara
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Jan 16, 2021
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"The gills are full of capillaries, a series of small and branching blood vessels."

"Other fixtures, such as air stones, bubble wands, bubble disks and power heads add oxygen and circulate the tank water."

"As water warms the amount of dissolved oxygen it can hold decreases."
 

FJB

Blue Tier VIP
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Dec 15, 2017
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Airation does not add oxygen per se. It adds atmospheric air. What is most significant is that the air current through the water brings water from lower levels of the tank to the surface, where gas exchange can occur. The value is the gas exchange at the surface, and the constant water circulation in a cyclic manner.
 

phreeflow

Goliath Tigerfish
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Nov 19, 2007
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The bubbles are too large and travel through the water too fast to add much oxygen. Even with carbon dioxide, planted tank keepers use diffusers to create smaller bubbles and all sorts of contraptions to make sure the dwell time is increased. Surface agitation is a more efficient way to increase dissolved oxygen levels
 

CichlidFiend

Plecostomus
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Oct 25, 2007
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The water in your aquarium contains dissolved gasses, to simplify we'll just say o2 and co2
In aquariums the exchange of dissolved gases happens in the fish themselves, as they remove o2 from the water they breathe in and add co2 into the water they breathe out,
It also happens at the surface of the water, water naturally absorbs o2 from the air and gases off co2, the water at the top becomes o2 rich and co2 poor. This is where aeration and water movement/circulation is important, you want to make sure that o2 poor water that has been expelled in fish respiration can replace the o2 rich water at the surface that has already gassed most of the co2.
Dissolved o2 is also consumed by bacteria, and plants also remove dissolved co2 gas and add dissolved o2 gas, some other examples of dissolved gas exchange in an aquarium.
I know this is especially important in saltwater fishkeeping, as different levels of o2 and co2 saturation can cause various diseases and illnesses in their livestock.
Hope this helps give you a decent foothold to help direct your research.
 

Backfromthedead

Potamotrygon
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The bubbles are too large and travel through the water too fast to add much oxygen. Even with carbon dioxide, planted tank keepers use diffusers to create smaller bubbles and all sorts of contraptions to make sure the dwell time is increased. Surface agitation is a more efficient way to increase dissolved oxygen levels
Don't understand your logic here....the air in bubbles is somehow inferior to the air that agitates the water surface?

Couldn't disagree with you more about the efficiency issue. Airstones themselves create surface agitation and air pumps are much more efficient than power filters or wavemakers in terms of power usage, and are much less prone to spontaneous failure ime, usually weakening gradually instead of seizing up like a pump or wavemaker.

There's also something to be said for the "upwelling" effect an airstone provides, saturating all levels of the tank with aerated water vs concentrating o2 rich water at the top.
 
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Fishman Dave

Potamotrygon
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Nov 14, 2015
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With a decent air pump and airstone, the amount of surface is increased significantly which in turn creates much more area for gas exchange. And when I say surface, I mean both the surface area around the bubbles hitting the surface and the volume of air travelling through the water column along with the original surface area of the tank.
Adding to the area of tank water meeting air will increase gas exchange, whether this is by airstone, wave maker, filter splash return, spray bar, trickle filter, etc. etc. some are more efficient than others (both cost wise and effectiveness) but at the end, the most efficient is the one which provides the largest air to water surface area over time, along with water movement.

As for planted tanks, the concept of co2 feed imo is purely a financial one. Co2 costs money, so making the bubbles the most efficient size relative to the time they spend in the water allows for the maximum exchange of co2 at the minimum cost. If bottles of co2 were free then we could just as easily pump bigger bubbles and more of them the same way we do with airstones and “throw away” semi depleated bubbles to atmosphere, BUT this then is also counter productive as we also increase the surface area and add more oxygen.
Much of the discussion over which is better, needed, best, etc. comes down to the individual, the individual tank, a cost factor, but mainly the stocking level and how much agitation is required.
 

fishdance

Redtail Catfish
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Jan 30, 2007
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I have oxygen meters. Unless your tank is over stocked, it's surprisingly how little oxygen fish need. No aeration needed, just fish occasionally swimming about.

However aeration is a good safeguard. To oxygenate, any water movement by water pump or aeration at all (any bubble size, any rate or volume) is sufficient.

A plastic mug to swirl water once an hour. An air line & almost closed air valve from inflated mattress etc will suffice through electrical black outs.
 
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aae0130

Candiru
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I was under the impression airstones couldn’t atomize air down to a level of enacting a molecular change in anything. Thought it was for agitation of the water surface……..movement…….and to increase flow throughput/bacteria surface if used in conjunction with a sponge filter or under gravel system.
 

Backfromthedead

Potamotrygon
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I was under the impression airstones couldn’t atomize air down to a level of enacting a molecular change in anything. Thought it was for agitation of the water surface……..movement…….and to increase flow throughput/bacteria surface if used in conjunction with a sponge filter or under gravel system.
Again...An air bubble is essentially a small air-water interface--just like the water surface in your tank but smaller. I'm still waiting for someone to explain to me how the air coming from a diffuser deep in a tank is any different than the air above the surface of the water and why exactly the bubbles would not exchange gases with the water column.

I'm starting to think desperate wavemaker salesman have been pitching this nonsense since wavemakers are pretty much obsolete now imo. Just like the whole "acrylic is safer than glass" garbage.

So yes, it is surface agitation that aerates your water, but the point I'm trying to make:

Air bubble=surface agitation

Why? Because the outside of an air bubble is actually just a surface of water! agitating itself via buoyancy through the water column!
 
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