Blackwater creeks and tributaries derive their name from their bronze tea coloured water, stained by peat, driftwood and decaying vegetation. Blackwater rivers are very low in dissolved minerals and often have no measurable water hardness.

Clearwater habitats exist in piedmont stream with substrate of rounded stones, gravel and sand where there is little erosion. Such waters are fairly common as creeks and rivers flowing through ancient rock, but are not abundant in lowland tropical rainforest. These rivers are fast-flowing at times, but slow-moving at others.

Whitewater originate in mountains that are still eroding large amount of mineral and soil. The water carry a high amount of suspended sediments, resulting in a muddy brown water with poor visibility. In the rainy season, the erosion causes many trees to fall in the rivers. Certain zones are colonized by water plants, but mostly, there is only wood and dead leaves.

Under good growing conditions, duckweed is an extremely fast growing plant that can double the area it covers in a day or two. I believe it is a really nice plant but it blocks the light, making other species hard to grow and I hate to have duckweek drip off the elbows everytime I stick my arms in the tank.

Here is an excellent and attractive addition to any freshwater tank. The Marimo ball, also known as Moss ball or Japanese moss ball is actually a filamentous green algae (Chlorophyta) found in a number of lakes in the northern hemisphere: Japan, United Kingdom, Russia, Iceland and Northern Europe.