Tetra nitrateminus size 250ml biological nitrate reduction in easy to use liquid format long term improvement of the water quality helps control the growth of algae for the permanent reduction of nitrate levels utilises natural processes within the aquarium to keep nitrate levels low and thus reduce algae growth long term reduction of the nitrate level to below 30 to 40 mgl higher dosages up to double strength can be used to decrease nitrate levels even further for both freshwater and mari