Subwassertang / Water Tang

Subwassertang (Lomariopsis lineata), also known as Round Pellia or Water Tang, is one of the more unusual plants in the freshwater hobby. Technically the gametophyte stage of a fern rather than a true moss, it forms dense, translucent deep-green lobes that look far more like seaweed than anything else in your aquascape. Native to Southeast Asia, it is denser than water and sinks naturally, making it far easier to anchor than most mosses.

Do not bury it. instead, wedge clumps into driftwood crevices, let them settle freely on hardscape, or tie them loosely to rocks. It adapts across a pH of 6.0–8.0 and temperatures of 18–30°C with no $CO_2$ or high lighting required. Keep it away from areas with very high water flow, as the delicate lobes can fragment and scatter. Liquid fertilizer, a touch of carbon supplement, or mineral additives for shrimp setups keeps it lush. Like most column feeders, it responds beautifully to fish waste – it grows noticeably better in our Discus and Angelfish systems.

Subwassertang’s finest role is as a shrimp sanctuary. The dense, overlapping layers provide constant biofilm for grazing and the safest possible refuge for newborn shrimplets. A firm favourite low-tech plant, available from Silverstream.