On Tue, 17 Dec 2002 07:05:03 -0000, "Philip Ash"
wrote:

I cant comment as to why your tank is shoing no change, but i have had the
same system on a 70 UKG tank for just over a week.
I have seen a drop in PH of around .3-.5
Are you sure about the accuracy/resolution of your PH test kit?
I have two different kits here. Before CO2 both showed about the same 7.5
Now one clearly shows 7.0 the other still looks like 7.5
I think this is due to the limits in accuracy/resolution/perception of
colour with the test kit.

hth
Phil.

I am most definitely not sure about the accuracy of my pH test kit.
Does any one have a recommendation as to one they have had good
experience with?

An update to my situation... I think I was able to get more dissolved
co2 into my tank by changing where the tube entered the diffuser.
This allowed the co2 to remain in contact with the water for a longer
period of time. Since then it appears that the pH level in my tank
dropped from 7.8 to about 7.2 or so. These are very unofficial as I
did not have my girlfriend to confirm (I am colorblind and the slight
changes in color are very hard for me to make out). However the water
does look slightly more green than blue. If I am right, that would
put co2 levels at about 15 ppm, a much more acceptable level. Thanks
for the suggestions.

NjF