help idk what this is

idk what this is i cant figure it out its destoryed leaves on only 1 plant my plantsare in flower only for few days tho and there getting bloom and tiger fox farm nutes 1tbsp of bloom 1tsp of tiger and there in ocean and forest 6.5ph they been fine for long time

calcium? whats your ph? water source?

I had the exact problem not too long ago, just stay ontop of your ph. Cleared mine up, spots wont go away but should stop. If not add some cal/mag to the mix

Calcium from lack of or pH..best wag.

ph is at solid 6.5 its on this 1 plant idk why itd have a mag def hmm unless its eating all nutes in soil like crazy ....