Ground limestone as calcium source?

[spacercaser]

I care for 7 sulcatas (and a few smaller tortoises) at work. Their previous keeper was using finely ground limestone as a calcium supplement, when they get veggies they are dusted with that instead of a mix marketed for reptiles. I think this was to save money, since tortoises that size need more calcium than all our other reptiles (which get a mix of calcium and minerals sold for that purpose). Will ground limestone work, or should I switch them to the more expensive stuff?

 

[katieandiggy]

I think limestone flour is Calcium Carbonate, or that’s what I’ve worked out from what I’ve read. But i stand to be corrected?

 

[Yvonne G]

Here ya go:

https://www.wattagnet.com/articles/24140-limestone-is-not-just-calcium-carbonate