Quote Originally Posted by RicMartin View Post
Turns out that in Hong Kong there's quite a cult-following for small fishtanks with six inches or so of light, calcium-heavy, gravel; full of Java Ferns, Java moss, and faster growing water plants. If the tank has the right load of cycle bacteria, and some snails, then, even without filters (I use one), they break down the ammonia and the plants take up the byproducts of that, leaving no food for algae to even grow, while also hyper-oxygenating the tank. The result is a tank that only needs a partial water change once a month, yet it's much healthier and stable water than what one gets from the high-maintainance, high chemical, style of fish-keeping.
Sounds very much like a Walstad Natural Planted tank! I followed these instructions for my 10 gallon and the plant growth boomed (mostly heavy root feeders like swords). My tank now is still planted in top soil but I cheated and added a filter.