Calcium injections for soft shelled eggs?

[Leela NH]

I have a 2 yr old Silver Gray Dorking hen that lays soft shelled and very thin shelled eggs. I was feeding a fermented feed and dry feed (grower mixed with whole grains, not layer) I have free choice oyster shell and limestone calcium chips.

I recently started feeding organic layer feed dry and continue to ferment the mixed grains. Her eggs are still coming out soft of thin shelled.

Should I inject her with Calcium Gluconate? How often and at what dosage?

Thanks very much!

Leela