DIY on a tank that size is not gonna give you the output needed to keep up
with your plants...

You may be at the proverbial crossroad, where you can spend the money needed
to provide your tank with the press. CO2, or you can eat.... I'd eat...

Regulators are getting more affordable every day... bottles as small as 10lb
are going for $50 here and there... keep trying to find the parts and
peices, you can scrounge up enough over a few weeks/months to get the whole
system.....



I could increase the number of CO2 jugs. I get about 3 or 4 small bubbles
per second right now. It's being injected into my Eheim canister intake.
My tank is a 75. I would like a compressed system, but cannot afford to
buy
it right now.