Well, I entered the world of CO2 injection this week and thus far, it
has been a disaster.

I have a 6'x2'x2' tank and sump that holds probably around 180 total
gallons of water. My tapwater is initially around 3 dKH and about 7.6 pH
(tested using Aquarium Pharmaceuticals tests). I added a couple
tablespoons of baking soda to raise the carbonate hardness to 6 dKH.

After doing some research, I read an earlier post by Tom Barr that
suggested introducing CO2 before worrying about lighting or trace
fertilizers. I currently only have two old 2' T12 flourescent bulbs that
came with the aquarium when I bought it (no telling how old the bulbs
are).

I got a JBJ combo regulator, solenoid, needle valve, check valve, &
bubble counter in the mail on Monday and attached it to my 10 lb CO2
tank. The high pressure gage read 800 psi (is this the normal reading
for a full tank?).

I ran about 12 inches of vinyl tubing (I know this is not ideal, but it
is a temporary solution until I can get some CO2 tubing or some Tygon R-
3603 tubing) to my CO2 reactor (CO2 & water entering the top, cascading
over bio-balls, and out the bottom back into the sump). There were no
bubbles coming out of my reactor, so I'm assuming 100% of the CO2 that
made it to the reactor was diffused.

I got some Ludwigia, Vals, Telanthera, and Swords to add. I dipped all
but the Vals in a Potassium Permanganete solution for a few minutes and
added all of them into a corner of the tank that had the two bulbs over
it.

I started bubbling at one bubble per second. and let it run through the
night. The next morning, my pH had not moved. I kept increasing the
bubble rate until it was going too fast for me to count (5 to 10 bubbles
per second!). After doing this a couple of days, my pH had only lowered
by 0.2 or 0.4 to around 7.2. The pressure on my tank had dropped by 300
psi so I scaled the bubble rate back to one per second. This morning, my
CO2 tank was flat empty.

Now, I'm assuming that I have a leak somewhere so I am switching to
silicone tubing over vinyl for now and I'm replacing the teflon tape on
the tank threads to the yellow stuff that's supposed to be for gas
connections and test for leaks with a soap solution, but I'm still
baffeled as to why I had to inject so much CO2 to barely budge my pH
levels. I confirmed the CO2 was making it into the reactor and I tested
the pH with water from the tank as well as water from the sump with no
difference. Is my pH test bad? My plants are turning brown and dying, so
I'm assuming the CO2 is not helping much (if any).

Any insights would be much appreciated.

Thanks.
-- Allan