C02 Diffuser?

[stuuk1]

Most of you will laugh but after a quick search Ive found nothing. I simply want to know what a C02 diffuser is? Why I'd decide that I need one?

Ive found plenty on how to make one but none to answer my questions...

Thanks!

 

[N0body Of The Goat]

It is basically a way of increasing the contact time between CO[sub]2[/sub] bubbles and your tank water, so that more of the gas can saturate the water. The Dennerle "ladder" diffuser also creates a little side-show whent my Danios go into hiding!

 

[OldMan47]

A diffuser, in simplest terms, is a device that is used to introduce a material, this time CO2, into a fluid. Ideal diffusers are ones which can promote good mixing of the material into the fluid. For CO2, a diffuser that is worth having is one that introduces CO2 into the water in a way that all of the gas is dissolved in the water and none escapes the water surface as bubbles. A ladder that is long enough can do this along with many kinds of things that break up the gas into really tiny bubbles. Another approach is a counter-flow reactor that has the bubbles rising in a small chamber and has water flowing in the other direction to dissolve the gas. A truly effective reactor design is a bit tricky but there are some out there that work well.

 

[waterdrop]

Yes, one interesting reactor design is a slightly enlarged cylinder spliced in to the input tube of a cannister filter and containing several bioballs. A CO2 gas line (with a one-way safety valve) injects CO2 bubbles into the cylinder, where the bioballs are being bounced around due to the filter water flow. The larger CO2 bubbles are broken up by the jiggling motion of the plastic and a spray of much smaller bubbles enters the filter box where presumably some become trapped in various places in the media. This should leave time for the dissolving to take place, hopefully prior to any collective buildup of CO2 that might leave the impeller without water (I've never heard of that being a problem.)

I believe simpler glass diffusers directly in the tank are still more popular than this type I've described, so perhaps there are other problems with this particular reactor approach. The planted tank folks would know.

~~waterdrop~~