Newa Circulation Wave Pump 5900 l-hNewa Wave 2, 5900l h specifically for planted aquariums to improve water distribution. For tanks of 250 600L In planted tanks, CO2 is rarely distributed correctly and as a result, algae grows. Similarly with nutrient distribution water tends to move in only one direction from the filter this simply isn't enough in a high tech tank. The addition of a Newa Circulation Pump solves this issue. Benefits: Very small only 9x6cm Sphere joint adjustable flow