Supernatant

Supernatant is the clear solution on top of a mixture, above any material that hasn’t dissolved. In reef keeping, the word comes up most with kalkwasser.

When you mix Bio-Kalkwasser™, only the clear supernatant should go into the aquarium. The white undissolved material stays out.

Why It’s Important

• It’s the part of a kalkwasser mix that’s meant to be dosed.
• The manufacturer is clear that the white undissolved material must not enter the aquarium.

How It Works

Mix the required amount of Bio-Kalkwasser™ with RODI water and mix well to dissolve. Drip the solution into the aquarium, letting only the supernatant enter.

The manufacturer recommends keeping air contact to a minimum, which reduces the undissolved particles that form.

Supernatant and Related Terms

Supernatant is the dosable part of kalkwasser. It’s mixed with RODI water, and how much stays dissolved is a question of solubility.

The Bottom Line

Supernatant is the clear top layer of a mix. With kalkwasser, dose the supernatant and leave the white sediment behind.