# Air Pumps and Air Stones, Oxygenation Systems



## yourockit (Aug 23, 2007)

Which airpumps and airstones create the most oxygenation in a tank?


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## piranawick (Dec 1, 2004)

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## NegativeSpin (Aug 1, 2007)

Whatever the brand you go for intuition would tell me you want an air stone that generates the smallest bubbles possible and placed as low as possible in the tank for maximum contact time. The smaller the bubble I would imagine you would need a pump that operates at a higher pressure to force air through a bunch of microscopic holes.


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## yourockit (Aug 23, 2007)

shanker said:


> Whatever the brand you go for intuition would tell me you want an air stone that generates the smallest bubbles possible and placed as low as possible in the tank for maximum contact time. The smaller the bubble I would imagine you would need a pump that operates at a higher pressure to force air through a bunch of microscopic holes.


very good. sounds right to me too. do you recomend any brand or brands of pumps and bubble stones or pads in particular?


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## XSPhoto (Sep 26, 2007)

While this may not have the smallest bubbles, it definitely puts out a lot, and is well worth the cash.

http://www.petsmart.com/product/index.jsp?...ly&keepsr=1


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## ZOSICK (May 25, 2005)

I agree with XS but if your filters have a good amount of surface agitation you don't need an air stone...


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## NegativeSpin (Aug 1, 2007)

I do remember reading that it is the surface agitation that does most of the aeration even if it is from the bubbles breaking at the surface but I would like to see a more scientific study done on this.


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## yourockit (Aug 23, 2007)

Surface agitation so that oxygen can get into the water? What about Co2 injection systems? Are they worth the money? How expensive are they? Thanks guys.


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## yourockit (Aug 23, 2007)

Co2 injetion system or airstone? 
http://www.aquatic-store.com/en-us/dept_16.html
Why is a Co2 system better? If only a few bubbles are released per second by an injection system then how is it that the water is being saturated with oxygen? Airstones release dozens of bubbles per second so why is the Co2 system better? How do these things work? thanks.


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## yourockit (Aug 23, 2007)

*from an internet article on aquarium aeration:*

SIZE AND AMOUNT OF AIR BUBBLES
Take a look at at the air bubbles produced by an aquarium aerator. Watch how quickly the bubbles rise to the surface. They provide little aeration, but are aesthetically pleasing to watch. Bubbles must remain contacting the water, if they are to do the job properly. A good rule of thumb is: The smaller the bubble, the longer it will remain suspended in water to dissolve.

OXYGEN REGULATORS, DIFFUSERS, AND CYLINDERS

Fishing regulators use a CG540 valve to connect the regulator to the oxygen cylinder. The cylinder can be filled at most welding shops. They are never used for medical purposes.

Marine grade fishing regulators are exposed to the marine elements and are made of brass with nickel plating. Aluminum regulators can corrode in salt air and water, and should be avoided. They can be either a needle valve or rotating barrel with preset openings. Only small amounts of oxygen is needed to maintain fish so the first settings are very small.

Never lubricate or spray your regulator. This will contaminate the regulator and may render it inoperative.

The diffuser is probably the most important item of your equipment. Inexpensive air stones waste precious oxygen. Bubbles are large and do not maintain contact with the water long enough, and are little use to good oxygenation. Diffusers are made of ceramic with tightly formed pores. The require 25 to 35 lbs of pressure to force the oxygen through ceramic pores, resulting in micro-fine bubbles. The bubbles are so small that they stay suspended in the water and the water absorbs the oxygen. Ceramic diffusers will give many years of service. If the pores clog at the surface due to impurities in the water, a light sanding on the ceramic surface will generally solve the problem.

Oxygen cylinders usually come in three sizes, made of aluminum to prevent rust spots on your boat, and use the CG540 welding valve. Use the largest cylinder that will fit on your boat comfortably. The cost of refilling a cylinder is generally the same, so there are substantial savings if you are fishing frequently.

Some welding shops have programs where you can purchase your cylinder and trade it for another filled cylinder immediately. The only disadvantage to this type of program is that the cylinders are steel and care must be taken to prevent rust spots on your boat.

Care must be taken to secure the high pressure cylinder securely to your boat. Do not secure your cylinder in a closed compartment.

*Answer:* oxygen injetors aerate water far better than air pumps do. air pumps with airstones will not really aerate a tank. they most one will get from an airstone is surface agitation. dalpa Co2 systems seem to be good systems to get. But I have not researched the systems nor read product reviews and made product comparisons. once set up, a co2 injection system will cost less than $10 per year for a large tank. Also, one can kill one's fishes with too much oxygen injection, so a precise system and monitoring system is required.


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## Lowporkwa (Mar 24, 2007)

you dont use a co2 injector to put oxygen in the tank, rather you use it to put ...gasp...co2 in the tank. The only reason one would ever use a co2 system is they are growing large amounts of live plants with a powerful lighting system! thats it! And as long as the surface of your water isnt completely still, you will have enough oxygenation. IMO only use bubble walls etc if you like the look of them or have a completely overstocked tank


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## yourockit (Aug 23, 2007)

Lowporkwa said:


> you dont use a co2 injector to put oxygen in the tank, rather you use it to put ...gasp...co2 in the tank. The only reason one would ever use a co2 system is they are growing large amounts of live plants with a powerful lighting system! thats it! And as long as the surface of your water isnt completely still, you will have enough oxygenation. IMO only use bubble walls etc if you like the look of them or have a completely overstocked tank


Is this correct?:

fish breath oxygen and release co2 which is taken up by plants and processed back into oxygen. if you inject a ton of co2 into oyour system your plants will grow larger and therefore process more co2 into oxygen which will be beneficial for the fishes.
[/quote]

How does oxygen enter the water of a tank? Do oxygen molecules hit the surface of a body of water and stick to the surface tension and then get sucked below the surface and mixed with the water so long as there is movement in the surface of the water?


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## XSPhoto (Sep 26, 2007)

Yes, You're correct. Like Humans, fish only need a certain percentage of oxygen in order to perform properly. IIRC human oxygen toleration is somewhere between 20-25%. Plants do provide extra oxygen through photosynthesis, therefor giving fish more oxygen to breathe.

Oxygen is entered into the water just like any other chemical does. It's a combination of dipole moments, capillary actions, and other things as well. Oxygen does not stick to the surface tension, the surface tension keeps oxygen from entering into the water, which is why having movement on or close to the surface is a key element to providing your fish with a breath of fresh air.


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## NegativeSpin (Aug 1, 2007)

I don't want to be kicked off the forum for advocating using lower temperature water for your fish but the solubility of gases in water decreases as the temperature goes up and water that is 70 degrees can hold 14 percent more oxygen than water that is 84 degrees. I'll probably just stick with the 79 degree setpoint on my heaters and have a 5 percent more oxygen advantage.


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