[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: CO2 equipment questions

> ------------------------------
> Date: Tue, 4 Dec 2001 18:47:55 -0500
> From: "Mary Alice Kropp" <mak at thirtytwopaws_com>
> Subject: CO2 equipment questions
> I am finally going to get a CO2 tank for my 55 gallon aquarium! (Thanks to
> my in-laws, who sent early Christmas money!! :) ) We have located a local
> source for the tank itself and the regulator, but I have a few more
> questions.
> 1) Do I need a needle valve? Or should I use one, whether specifically
> needed or not?

Yes, IMO, it is a vital item, but does not have to be terribly expensive. It
takes the low-pressure CO2 from the regulator, and makes a more-or-less
constant flow volume out to the diffuser. Small changes in tank or regulator
pressure don't cause huge flow differences to happen through a needle valve.

> 2) Is the Eheim diffuser a good one? It seems so inexpensive compared to
> others. I'm not against saving a bit of money, but I just want to make sure
> I get the right stuff for the money.

The Eheim worked very well for me in several tanks, after I got rid of the
check valve that might cause end-of-tank dumping problems. It has a built-in
bubble counter and is well made, I think. YMMV.

I think Tom Barr's sort of reactor is likely to be more efficient,
particularly if your tank isn't tightly covered. Mine always were.

> 3) What about CO2 resistant tubing? It's rather expensive, but is it worth
> it? Or would silicone tubing be good enough?

Silicone tubing (the rubbery blue-green stuff) is *supposed* to be CO2
resistant, and at our low regulator outlet pressures (usually 15 psi or less)
it should be pretty good. Vinyl tubing (clear and stiffer) may show long term
damage from the gas, but I have never observed that myself.

> 4) A bubble counter? Yes or no? Easier or not necessary?

Essential, IMHO, if only so you can see any changes in flow rate from
variables you overlooked (like the Eheim check valve). It lets you set the
needle valve to the flow rate you need.

> 5) What about fittings? Though I suppose the guys at the place where we get
> the tank and regulator ought to be able to help with that, right?

Find your local Clippard dealer. They will carry other brands, too, and they
will be the kind of stuff you want, usually. The tank/regulator dealer should
do anything up to the hose, just fine. Good inexpensive needle valves and
multi-outlet manifolds are more industrial items they will not have.

The silicone tubing is easily "ballooned" by the CO2, and will eventually slip
off poorly fitted barb connectors. I used drip-irrigation fittings for Tees
and couplers, but put a wire twist tie on each joint to prevent blowing them
off with time or if I set the regulator a bit too high. [You don't want them
blowing off while you are away and dumping your whole tank.]


Wright Huntley -- 650 856-4245 -- 879 Clara Dr. Palo Alto CA 94303

The San Francisco Bay Area Killifish Assn. (BAKA) has a new web
site at:  http://www.sfbaka.net.        [I'm the proud Web Poppa.]