dKH

What does dKH mean?

dKH (degrees of Carbonate Hardness) measures the buffering capacity (alkalinity) of aquarium water, specifically the bicarbonate + carbonate concentration. Higher dKH = more resistance to pH swings.

How is dKH used in aquariums?

Reef tanks target 8-12 dKH (most stable at 8-9 dKH). Freshwater planted tanks run 3-8 dKH typically. Test with a Salifert or Hanna alk checker; swings of more than 1 dKH per 24 hours stress coral.

How dKH fits the bigger picture

Understanding dKH matters because it's connected to broader husbandry decisions: water chemistry is the foundation of every other aquarium parameter - chemistry mistakes show up months later as livestock loss.

Browse the Fast Aquatics care library for full husbandry tutorials covering dKH in context.

Frequently asked questions

What does dKH mean in fishkeeping?

dKH (degrees of Carbonate Hardness) measures the buffering capacity (alkalinity) of aquarium water, specifically the bicarbonate + carbonate concentration. Higher dKH = more resistance to pH swings. Reef tanks target 8-12 dKH (most stable at 8-9 dKH). Freshwater planted tanks run 3-8 dKH typically. Test with a Salifert or Hanna alk checker; swings of more than 1 dKH per 24 hours stress coral.