Re: Aquatic Plants Digest V1 #388

>From: Hextek at aol_com
>Date: Thu, 4 Apr 1996 18:24:33 -0500
>Subject: CO2 Tanks
>I would be interested to know for those who use compressed CO2 cylinders for
>their planted tanks, how often the cylinder needs to be refilled.  I suppose
>the main criteria for CO2 consumption is aquarium volume, plant/fish load and
>target pH.  Please include this info. in your respose.

I use a 20 lb tank (I think it's 20 lb; it's 22 inches high at the neck and
7 inches in diameter) for a heavily planted 75 gal tank. I bubble the CO2
into a CO2 bell at about 1 - 2  bubbles per second. The tank itself costed
$105 at a welding supply store. A full tank lasts me at least 6-8 months and
costs me $11 to refill (actually, they just trade me a full tank for my
empty one). I grow a diverse assemblage of plants (e.g. Echinodorus major,
Cryptocoryne becketii, Aponogeton crispus, Nymphaea sp., Rotala macrandra,
Microsorium pteropus, etc). I don't think any of my plants are difficult
plants but adding CO2 really helped. For anyone thinking about having live
aquarium plants as a long term endeavor, having compressed CO2 is a
worthwhile investment IMHO. 

By the way, the pH of our city tap water is 7.8 (measured using a Hach One
pH meter) and the water in the tank stablizes at around 6.8 after a few days
(I do 50% water changes about once every 10 days). I must admit that I don't
really pay much attention to the pH because the fishes (angels, rams and
corys) appear happy and breed often and the plants grow rapidly. The
alkalinity of the tap water is 75 ppm CaCO3 (measured using a Hach
alkalinity test kit, model AL-AP MG-L). Hope this helps and good luck.

Shiao Y. Wang
Univ. of Southern Mississippi
sywang at whale_st.usm.edu