Blackwater ponds, creeks, and rivers originate in the rain-forest. In the slow-moving waters, acids are leeched from decaying vegetation creating very transparent, tea-colored water. These waters have almost no measurable water hardness and an acidic pH.
The substrate in blackwater habitats is typically leaf litter over a base of fine clay or sand. Decaying wood and plant matter is common especially in flooded igapo forest. There are many submerged terrestrial plants, many of which retain most of their leaves.
This is a good idea for a thread. I've considered doing these because I really like the look of tannin stained water. However I haven't seen any good examples of planted versions, and I don't know how well that would work. I sort of assume you'd need low light plants, but I'm not sure.
My girlfriend has a blackwater setup. 20 gallons. Not really intended to be. But the driftwood has leached tanins for about 5 months now. Lighting is an 8k LFL. Just a bunch of guppies she has accumulated and a colony of cherry and ghost shrimp, oto's and assasin snails. And a variety of plants just chunked in there. Ill post a pic if ya want