"Carbonate hardness test • Recommended level in freshwater: 4 - 8° dKH (GKH) • 1 drop = 1° dKH (GKH). • Colour change from blue to yellow. • For fresh- and saltwater. Product description The JBL KH Test Set is an easy to use quick-test for determining the carbonate hardness or the antacid capacity of saltwater and freshwater. (Recommended level in freshwater: 4 - 8° dKH (GCH)) Problem solutions The carbonate hardness The carbonate hardness CH is one of the most important water parameters in aquarium keeping and for garden ponds. The CH stabilises the pH-level and therefore prevents any dreaded plunge or sudden steep rise in pH levels, both of which are equally dangerous. In normal community aquariums and ponds, the CH should never drop below 4° GCH. Even if the initial water contained sufficient CH levels, the CH in the aquarium and pond may decrease. This may be the result of vigorous bacterial activity or a lack of CO2 - with plants and algae extracting the CO2 they require from the CH. Consequently the CH decreases and the pH-level is unstable.
The CH in the freshwater aquarium can be increased by: 1. The addition of JBL AquaDur plus (increases TH and CH) 2. The addition of JBL AquaDur Malawi/Tanganyika (increases CH higher than TH) The CH in the garden pond can be increased by: 1. The addition of JBL Alkalon Combi (increases TH and CH) The CH in the saltwater aquarium can be increased by: 1. The addition of JBL CalciuMarin (increases CH, calcium and strontium) The CH in the freshwater aquarium can be reduced by: 1. Filtering through JBL Tormec (black turf granulate) (only minor reduction possible) 2. The addition of JBL Aquacid pH-reducer (careful: in small steps!!!) 3. The use of reverse osmosis equipment (JBL Osmose 120) (removes CH and TH) "