I'm a newbie so i may be way off on this...

There are two cases:

If you DO NOT HAVE CO2 injection, then you need surface agitation to
maximize
CO2 diffusion from the atmosphere into the water.

If you have any type of CO2 injection (DIY or pressurized), then you want
to
minimize surface agitation to minimize CO2 loss from the water.

is there a case on a non-injected tank to have to much agitation to reduce
CO2 than would otherwise? (meaning, fish giving off more CO2 in the tank and
if you agitate it too much it would actually take out the CO2 from the
water)? or is fish respiration never great enough to create that kind of
imbalance/supersaturation in a soft, alkaline water?

Phyl told me not to use bubble agitation (venturi), as that will cause the
CO2 to escape too much (she knows I don't have CO2 injection)... so I'm
just wondering...

linda