Carbonate Hardness (KH)

Carbonate Hardness (KH) is similar to general hardness. However, instead of measuring calcium and magnesium ions, it measures carbonate and bicarbonate ions. The higher the KH, the more stable the PH. Although KH is indeed beneficial, excess KH will stress your discus. For that reason, KH must be maintained at a stable and suitable level at all times. The KH needs to be at a level where it won’t affect the breeding patterns of your discus. We recommended a KH of 1 – 2 for breeding tanks. Display tanks, however, are best suited to a KH of between 5 – 8, as this makes the PH far more manageable. The same principle of GH in rearing tanks applies to KH. The KH needs to be gradually raised so that the juveniles can benefit from the minerals that a higher KH provides. Gruadually raising the KH will also help to stabilize the PH, as juveniles are extremely delicate to any changes in their water conditions. A KH of 5 – 8 in a rearing tank is ideal for growth and PH management.

Carbonate Hardness Test Kit

Carbonate Hardness Stabilizer

QUESTIONS

• Why is it important to monitor your discus aquarium’s carbonate hardness (KH)?
• How do different KH levels impact your discus aquarium?
• If you need to change your tank’s KH level, what methods would you use?