Calcium standard

[Cory]

Is there a diy calcium standard to test my kit with? 3 kits all read different. I have on hand kents turbo calcium.

 

[Randy Holmes-Farley Verified Community Expert]

It’s not trivial to develop a Diy standard that is a good test of kit accuracy because it should be seawater with calcium in it. A simple calcium solution doesn’t stress the kit capability.

 

[blasterman]

Take the one in the middle.

Or, mix up some Instant Ocean as a reference. Calcium tends to be 360-400 with that product.

Shoot for a calcium level of 400 and dont worry about it. That will give you plenty of wiggle room.