Brown spots on leaves

[HL2200]

Please help!! 5/9 of our plants are getting these spots. We just changed light schedule from 12/12 to 20/4, could it be light burn? Haven’t given nutes in a week, they are af and different strains. Thx!

[willythepic]

I think Calcium deficiencies cause tiny brown spots but I'm not sure

[SoOrbudgal]

Hey willy you got preflower yet?

[HL2200]

Thank you so much! I did a little research and it does look/sound like what’s happening. Really appreciate it!