Water testing for experienced aquarists

 
Experienced aquarists check their aquarium water regularly. This allows taking measures, for instance against algae, quickly and easily, without the need to use chemicals.
The sera aqua-test box contains the following test kits:
pH value (pH)
total hardness (GH)
carbonate hardness (KH)
ammonium/ammonia (NH4/NH3)
nitrite (NO2)
nitrate (NO3)
phosphate (PO4)
iron (Fe) and
copper (Cu) or chlorine (Cl)