Does two part (RHF recipe 1, part 2) have a shelf life?

[jenreefer]

I mixed up some baked baking soda (Alkalinity recipe 1 part 2) about 5 months ago. My tank usage was very low at first (new tank) but now is increasing rapidly. I am adjusting alk and ca daily to find my new normal. All SPS is currently growing with no current die off.
My question is two part:
1. Is there a shelf life for either ca or alk after it is mixed?
2. Is it common to have a sharp increase in demand of ca and alk in a 6 month old tank?

 

[Randy Holmes-Farley]

They will last longer than the container you put them in.

Yes, as corals and coralline start to take off, demand for alk and calcum increase.