The CO2 Glass Reactor 100 has been developed for the fertilisation of freshwater aquaria. The unit has been especially designed for in-tank use. The reactor is maintenance free. If, after a longer period of operation, the ceramic diaphragm is clogged, you can clean it by placing it for a few days into 6% hydrogen peroxide solution. Reactor is approx. 2.5" high. Comes complete with suction cup holder.