Silicon (abbreviation Si) occurs in water as silicic acid or silicate. These substances are important nutrients for the so-called primary production (= beginning of the food chain). Also, Si is important for some corals, sponges and planktonic organisms.
Too much, however, can cause real diatom plagues. Dense diatom carpets can strangle sensitive corals and do not look nice.
Sources:
Silica can come from decoration material (ceramic materials), from food and from unsuitable bottom material. Si cannot diffuse out of aquarium glass.
Sinks:
Silica can be removed from the water with phosphate adsorbers. If the silica enters the aquarium with fresh water, the water treatment should be checked. Even reverse osmosis systems can only remove part of the silicic acid. A downstream ultrapure water filter can safely remove the silicic acid.
It is hardly possible to give a limit as to when diatoms become a plague. Some aquariums do not show any infestation at silicate concentrations of more than 1 mg/l. In other systems, plagues can already occur at less than 0.2 mg/l.
0.25 to 0.5 mg/l should not be exceeded.
Phosphate-X-globuli for phosphate removal
Phosphate adsorber with good cost-performance ratio
Ultrapure water filter in GRP tank
10" ultra pure water filter