CO2 Consumption with misters


Junior Poster
Jun 17, 2006
Durham, NC
I'm pretty confused (again).

I have a 180G tank and I have had, as you might expect, problems getting enough CO2 into the tank.

I decided to try the misters... so I bought three of the Rhinox 2" diameter misters (these are big). I also invested in some nice needle valves to distribute the gas.

In order to get any bubbles out, I had to crank the pressure up pretty high. The stones are so dense that the pressure has to be high. I tried to blow through the intake and it was a lot harder than say manually blowing up skinny balloons.

So anyway, I get a lot of bubbles in the tank. LOTS of bubbles. Not a lot of growth mind you. But lots of bubbles. The entire top of the tank is even covered in 'em. Well, except where I have some small pumps creating some turbulance to help with gas exchange. The fish are fine. No signs of stress. I even have happy otos.

The problem is that I'm going through CO2 like mad. I have checked the system for leaks (using soap bubbles)... but I don't see any.

Does the mister method use a lot more CO2 than the reactor method? Seems like it must. How many pounds of pressurized CO2 would you expect to use on a 180G say per month?

Thanks! - Chris


Lifetime Charter Member
Lifetime Member
May 4, 2006
Thank you! I thought *I* was crazy!

I'm using one of the Rhinox misters (forget the model) on a 20 long, and I'm using up a 5lb CO2 canister every 1-2 weeks, depending upon how many bubbles per second I'm using as I experiment. Regardless, it seems to go through quickly! Luckily I have a contact that I can refill at $6, but still, it's a lot more than I thought I would.

I am using one of the Rex Grigg setups with a low-pressure regulator and needle valve. I found I had to tape over the LPR's vent to prevent the gas escaping there. Only recently did I reson that that was where a lot of the gas was escaping.

Also, those Rhinox (or similar) diffusers do not work with DIY CO2 setups, they cannot generate enough pressure.

Tom Barr

Staff member
Jan 23, 2005
Generally we used about 20lb tank every 1-2 years using misters for a 150-200 gallon tank.

Leaks etc sound like an issue.

Tom Barr

[email protected]

Junior Poster
Dec 12, 2010
CO2 Consumption

I know this thread is old....I just got back into aquariums again as the boys all wanted their own tanks....

Based on my calcs:
Assume the CO2 bubble is 1mm^3
Assume the actual pressure of the bubble is 14.7 psia
1 bubble per second is 0.343 lb/day
If the it takes 0.5 psi to get through the diffuser, then the bubble is 15.2 psia
1 bubble per second is 0.356 lb/day
For a 20 lb tank to last a year you have to flow 1 bubble every 6.5 seconds
( I did this math cause I burned through a 20 lb cyl in a month...I was flowing a bubble a sec in two tanks and figured I had a leak...couldn't find one so I did the math...2 bubbles a sec should last a month...going to see if I can slow it down some)


Guru Class Expert
Oct 26, 2007
Brisbane, Australia
Hi Zeppelin,

Not quite sure what you are asking above (if in fact you are asking anything at all?) :)

I assume you are building a needle wheel for one of your aquariums and are wondering how long your 20lb bottle should last you?