"Djay" wrote in message
...

"Tim Stephens" wrote in message
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On Wed, 03 Sep 2003 21:05:05 +0000, Ghazanfar Ghori wrote:

Always keep an eye on pH. Determine your CO2 levels using the pH / KH
chart available on Chuck Gadds website. (works as long as you're not
using
any buffers). About 25-30ppm of CO2 should be your target.

How long does your CO2 last before you have to dump it and mix a new
batch?

When I was doing the DIY CO2 thing with yeast/sugar and water, I used to
get
about 8~10 days of consistent production. From about 28 hours after
mixing to about 11 days later then the co2 production would taper off
significantly. So to ensure that I was always getting max co2 into the
tank
I'd mix a batch every Saturday afternoon and swap the yeast/sugar/water
co2
generator every Sunday evening. I didn't use pop bottles but rather the
64oz juice bottles. The chemistry experiment was fun in the beginning but
the habit got old quick. I never experimented with adding baking soda to
the mixture to try and stretch the co2 production. That may work, but I
have no first hand experience with it. The DIY CO2 worked fine for my 37
gal tank....Plants flourished etc. However when I "upgraded" to a 70 gal
tank the DIY system could not keep up with the demand for CO2 and I had
serious difficulty with Ph swings throughout the day. Eventually, I lost
a
couple of fish and had serious battles with algae that I and others
attributed to unstable Ph. Turns out that the DIY system just couldn't
produce enough CO2. Couldn't take it anylonger and so for around $100 I
added a pressurized CO2 system to my tank and have never looked back.


DJay


I use 1/4 teaspoon of yeast and 1/4 teaspoon of baking soda with my Hagen
Co2 units and I find that I am getting 21 days of expectable bubble
production from each.
As I have very soft water I raised my KH level from 30ppm to 100ppm and find
my pH sits on 7. Before I raised the KH my pH was all over the place.This
gives me a CO2 level of 18 mg/l, which I am happy with.

Tony