Kalk Precip

[Beverly]

Have been dripping Kent kalk mixed with RO/DI water off and on for several months with great success in my three tanks.

After my last water change on the three tanks, this past weekend, the kalk drips into the water and then it precipitates. It looks like it's snowing. In all three tanks

Haven't done complete alk, calcium, magnesium tests on any of the tanks. I'm sure they are all at least slightly different in chemistry, so I'm thinking my kalk powder is getting old.

What do you think?