"Paul Davies" wrote in message ...
You make some interesting points. Coincidentally, my tap water is, like
yours only 60-70ppm carbonate. In my 100gallon tank, at 2 bubbles per second
My question is :- are you saying that adding baking soda will give me "free"
CO2?

No, it will only scale up the pH range you need to have a good CO2
level in your tank.

A KH of 50ppm(~3 degrees) needs a pH of about 6.5 or so.
A KH of 350(~20 degrees) needs a pH of 7.3.

Both have the same amount of CO2.

One has more Total carbon(CO2 + HCO3) but both have the same amount of
CO2.

CO2 is what the plant wants.

Just figuire out a way to get more into the tank or increase the
efficiency of the method which you are dissolving the gas.

Regarding trickle filter CO2 losses: it's not the bio tower part, it's
the over flow and splashing etc. Sealed trickle sections should not
lose any CO2 gases. See George's, Steve's and my comments on the APD
regarding this.

If you could possibly do a little more to convince me, I will
certainly
give it a try.
I think that my CO2 injection rate is so high because I am using the BioLife
combined trickle and conventional filters, but can't think of a good way to
deactivate the trickle section. Does anyone have any ideas?
Paul Davies

Regards,
Tom Barr