Not answering your question but wondering if using hydrochloric acid is safe
given that it will liberate chlorine in your aquarium?

Keith

"Chris Crochet" wrote in message
om...
Newbie to CO2 injection needs help.

My setup:

10 gal. freshwater aquarium
2x 23W 5000K lights (4.6W/gallon)
Natural gravel substrate
Assorted plants and fish
Ghost shrimp
Malaysian ramshorn snails
Aquaclear filter
DIY CO2 injection (6 bubbles/minute into filter)
Airstone (used when lights are off)
Heater (75°F)
PMDD

My tapwater is around 8.4 pH (as tested with a high-range kit). The
CO2 lowers the pH some, and I lower it the rest of the way to 7.0-7.2
using dilute hydrochloric acid. A bit unorthodox, but I will never
use pH-Down or any other phosphate-based buffer again -- I like to be
able to see the contents of my aquarium, not just algae. I don't
currently know the GH/KH of my water, but I assume it must be pretty
high.

Plants are growing a bit better, with a little pearling at the very
top of the aquarium close to the lights. However, CO2 still seems to
be a limiting factor. I know this because I used a bad CO2 recipe the
first time, which generated far too much CO2, crashing the pH below
the bottom limit of my test kit. The result was insanely fast plant
growth, and pearling all over. Unfortunately, the snails were
suffering rapid shell damage. (The fish seemed unaffected.)

I want to see that awesome plant growth again, but I don't want a
bunch of naked snails, so:

1) At how low a pH can the malaysian ramhorn snails thrive on a
permanent basis?
2) Will it benefit the plants if I add more CO2, and use less
hydrochloric acid, while maintaining the same pH? Or is the CO2
already sufficient, but not directly available to the plants because
of my current pH of 7.0-7.2?

And a few other questions:

3) How do you acclimate fish to a CO2-injected tank? Normally, I'd do
a slow acclimation over a few hours by adding tank water to the
container the fish is in, but with CO2 leaving the water and raising
the pH once it leaves the tank, I'm not sure how well this would work
anymore.
4) After the accident, I was *not* able to bring the pH back up after
removal of the CO2 and vigorous aeration over two days. It took water
changes to bring it back up. Did I cause some non-reversable chemical
reaction?
5) Though I don't have this problem right now, could you cure an
aquarium of a pond snail infestation by simply lowering the pH with
CO2 for a few weeks, destroying their shells?

Thanks in advance!
Chris