De-Chlorinator in the green bottle is very good for a stop gap due to low funds. $2.99 at the LFS, made for 1000 gallons...supposedly.
Besides, if you're doing 30-40 gallons per week for two tanks...unless you have a couple 125's at your house...that's plenty to keep all the things in check for quite some time.
But, really...once the funds pick up, seriously consider Prime. I started off with Stress Coat and burned right through the squirt bottles in no time. A 250ml bottle of Prime lasts me at least three times longer. Still have the same bottle I picked up in February and that's after an entire tank breakdown and rebuild.
The longer I'm involved in this hobby the more & more I'm convinced that Bio-Type species tanks are the way to go. Plants and fish/inverts live together in nature for a reason. I find the less I try to fight nature the better my tanks look.
- DogFish 1.24.12