Sand as a source of calcium?

I live in Florida and my up and coming food forest is grown mostly in sand. The sand here comes primarily from broken up seashells and some coral. I was thinking the other day, does that mean I have all the calcium in the world that my plants need and can stop crushing these eggshells?

Thanks!

Yes, shell contains calcium and many other micronutrients... except calcium availability is low with low pH, which is common because, free calcium and other positively charged nutrients don't stick to sand soils if they are short clay or organic matter due to low cation exchange capacity. So probably no problem with calcium as long as you organic matter/soil food webs are working, would be my guess... but I have absolutely no experience in your kind of system, so if someone else doesn't have a better story, I'd talk to someone like a local extension agent about how those soils behave, and then reinterpret their knowledge in a whole soils framework as necessary.

For calcium I bury pet hair I save from grooming my animals. I put it in the bottom of the hole when planting - works well, especially with tomatoes.

Charles Kelm wrote:For calcium I bury pet hair I save from grooming my animals. I put it in the bottom of the hole when planting - works well, especially with tomatoes.

I add my own hair, when I cut it.
I also add my own cut nails.
And all those egg shells.
I also add all waste from fruits, citrus included.

These are precious calcium resources I do not want to waste