3 1/2 months ago I setup a 75gal planted tank. Being strapped on cash for the project, I decided to do the DIY co2 thing for a while to save up for a pressurized system. I finally got the funds together last week and ordered my pressurized co2 rig, but I wanted to share my success with my DIY setup.
I work with a home brewer who has been brewing beer and wine for a lot of years. I was talking with him about this setup and I explained what I was doing. When I mentioned that the DIY rig would only last about a month and need to be redone, he asked why I would dump out the "juice" and restart from scratch. He said that just adding more food (sugar) should start the whole yeast reaction up again.
So I setup a typical DIY 2 liter rig with (2) 2 liter bottles for generators and (1) 2 liter as the check valve of sorts. Instead of using straight up sugar though, I bought a ginormous jar of grape jelly from the supermarket for $1.97. I started the concoction off with around 8 teaspoons of grape jelly. This initial mix lasted about 30 days at 2-3 bbs of co2 production. When it started to taper off after 30 days, instead of dumping it off, I just started adding 4-8 teaspoons of jelly every Sunday with a water change.
It's going on 4 months now of constant co2 production and it actually seems to be producing more co2 now than it did in the first 30 days. Whats also interesting is that the mix looks and smells like wine. I did taste a swig (much to my wife's dismay) and it actually tasted pretty good.
This was just regular red star bakers yeast to start the mix off. I used one packet for both 2 liters and disolved it in luke warm water.
Just thought I'd share. I haven't seen much on using grape jelly on the forums. It certainly was economical and I'm almost tempted to keep it running to see how long it will last. It definetly has a high alchohol content at this point and that obviously hasn't killed the yeast off, which is what I had read. But then if you think about naturally carbonated beverages, they don't stop producing co2 even when the alchohol content is high.
The pic below was about 2 weeks after setup. I have 16 neon tetras, 7 pristella tetras, 4 cories and 2 siamese algae eaters. I have to admit that I had a fish die about a week ago from unknown causes and the growth is so thick in this tank that I didn't see him. It fouled the water and I got a bad green water outbreak that I've almost got licked now.