beach sand or calcium carbonate for increasing buffer/hardness without raising ph

[HelplessNewbie]

I was wondering if I could use beach sand and/or seashells collected years ago from Destin to gently raise buffer without raising ph? What about calcium carbonate powder?

[nabokovfan87]

 This is a good place to start.

https://www.amazon.com/aquarium-leveling-mat/s?k=aquarium+leveling+mat

I recently started using equilibrium.  It works well. I like that it has some of the things plants need as well.