CO2 and pH changes
I have had a 20 gallon tank set up for a few months and have recently
undertaken measures to treat my plants a little better. I have increased
the lighting and begun using substrate and liquid fertilizers. This
week, I decided it would be fun to try DIY CO2 injection. So, I have
this setup with an old 2-liter bottle discharging through an airstone.
My problem is that I have very soft water coming from the tap. The Aq.
Pharmaceuticals hardness test shows about 40 ppm and the city water
report is consistent with this. So I am getting pretty large pH swings.
With any flow greater than a few airstone bubbles a second, I get a pH
drop on the order of 0.6-0.8 points. I have been adding a little bit of
baking soda to correct this, and am able to reduce this change to about
0.2 points. I don't mind doing this, but want to be sure that it's not
dangerous to my aquarium in non-pH ways.
The tank is 20gal, lighting is one 24" GE plant and aquarium and one
Phillips Daylight fl. bulb. I have five 3" angelfish, two corys, a clown
loach, and three otocinclus. Because of the angels, I don't want to use
a remedy which increases the hardness, if possible.
Thanks for any advice.