[gpodio]

Here's my take on DIY CO2

http://www.gpodio.com/diy_co2.asp

Nothing that hasn't been said before, John LeVasseur's writeup has been a long time favorite of mine. There are these two other pages from John that are worth reading:

DIY Reactor
http://www.qsl.net/w2wdx/aquaria/reactor.html

This one is very good...
http://www.qsl.net/w2wdx/aquaria/letter.html

Giancarlo Podio

 

[gpodio]

David, try to tighten the tubing around the nipple using some fishing line or a twist tie...

Hope that helps
Giancarlo Podio

 

[gpodio]

You have to be a little more careful obviously, the PH will follow the rate of CO2 which starts off high and tapers off over the course of the mixtures' lifespan. It depends how low your KH is, anything 2 or above should not be an issue in my opinion. If you take for example a tank with 2KH and a change in CO2 concentration from 25ppm to 15ppm, the change in PH is about 0.2. Now if the same occurred in a tank with KH5, the change is PH is still approximately 0.2. So the magnitude of the fluctuation is comparable, the resulting PH is what differs mostly.

Giancarlo