The instructions provided or the suggestions above will work just fine. I keep it in my son's lo-tech 20L inside an Aquaclear 50 all the time. Plants do just fine, fish are happy, ZERO ALGAE and water is like glass. Have to regenerate maybe once every six months once all the beads get dark brown/black.
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