Does Kalc powder have an expiration date?

[PedroYoung]

10 years ago I bought a Kalc reactor and Kalc powder as my intended primary Alk/Calc addition. At that time I was using the ATO to push RO water through the reactor but discontinued after a couple weeks due to the spikes in pH and lack of control over addition rate. Now 10 years later, I'm older, wiser, and have a much larger tank and want to fire up the reactor and use with a controllable peristaltic pump to make up some of the ATO as my 2 part dosing has started to climb dramatically. I have a couple containers of Kalc powder and certainly would like to use them, but just wondered if I'm missing something in my assesment that it should still be stable and effective???

 

[Randy Holmes-Farley Verified Community Expert]

Calcium hydroxide and calcium oxide will slowly be converted into calcium carbonate as CO2 and moisture enter the container. How fast that happens depends on the container, but 10 year old material may only be partly active.

 

[DanyL]

There’s no reason you wouldn’t be able to use it though.

Any kalk that was turned into Calcium Carbonate will be inert and simply won’t dissolve.

So the only real problem for you would be to determine when you’ve reached saturation, because you won’t be able to use precipitation as an indicator.
You could however measure the PH of the solution instead.

 

[PedroYoung]

@Randy Holmes-Farley

Thx for the reply!
1-any disposal considerations for old Kalk?
2-Can you point me to any of your previous articles on using Kalk? Wondering about Mg makeup which is currently included in my 2 part regimen.