"Shawn P. Good" wrote:

My main question however is about CO2. First, should I have it?
Second, if yes, why are they so expensive ? The CO2 systems I see
online and in catalogues seem to be very expensive. However, I saw
one online (again at www.thatfishplace.com) by Hagen that seems very
inexpensive and I was wondering what other people's opinions on it
are. The product is Nutrafin CO2 Natural Plant System (Hagen)

CO2 is rarely a bad thing for a planted tank, so you should at least
try it to see if it gives you a big benefit.

The price differences you see are between 'pro' systems versus
do-it-yourself systems. A pro system uses cylinders of CO2 gas,
regulators, and other components. In other words, it's a serious chunk
of hardware. It gives you consistent output, is useful for large
tanks, and is relatively maintenance free.

The DIY systems use yeast and sugar in common plastic bottles, and not
much else. This works for smaller tanks and is *very* cheap. It's not
as consistent, is a little harder to control, and requires more
maintenance. A net search on DIY CO2 will answer all your questions
about this method. It's very easy.

My advice would be to try the DIY method, since the cost of entry is
so low, and see how much of a difference it makes in your plants after
a month or two. If you like the plant results, then consider if the
cost of a canister system is worth it to you.

The Hagen system you mention is nothing more than a commercialized
version of the DIY systems. Basically, it's a plastic bottle and some
pre-packaged yeast. The one very nice thing it has is the diffuser
(which you can buy separately for under $10). This is the part that
goes in your tank and actually lets the CO2 bubbles dissolve into the
water. I used one here for several months (I no longer use CO2) and it
worked very well.

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