Calcite help?

I have calcite from old neutralize filter for the house for acid water and raise PH. Need to know as ideas of uses for it here in saltwater hobby.
I know it is calcium based. Here I read it used for sand beds.

Can I put it in a filter after my DI filter to help raise the calcium and the PH in my make up water? I know it will not raise a lot.
Need to know if it hurt anything.

As maybe help me cut back on some of 2 part dosing.

 

RO/DI water is fairly corrosive and will dissolve the calcite over time, but I'm not sure how much you would get.

I would try it and then do a calcium test on your RODI water after it has gone through the calcite to see how much you dissolve. If it's just a little bit, it could be a way to supplement your tank.

 

Just my opinion, but if it doesn't come with specific instructions on how to use it with a SW aquarium, I wouldn't even consider it. I'd hate to crash my tank by trying to use a shortcut. Obviously the chemical structure is different between calcite sand and water softener salt, then there's the question of purity...