Plant has brown rusty spots on fan leaves any suggestions

both my plants i have noticed have theys rusty looking spots on them . I am a newish grower i grew a crop 3 plants a few monthes ago with no problems at all. theys two plants i have now basically look like when your plant gets water on the leafs and the water magnifies the light and burns teh leaf. but all over the the fan leafs on most older fan leafs. any help would be appreciated. I have a black berry plant and a tangerine dream under a 250 watt HPS just switched to 12/12 yesterday in soil miracle grow which i have used in the past.

Spots start off brown then turn rust color? Id say a nute deficiency but there should be plenty of nutes in MG, check your ph by checking your runoff and make sure its coming out at about 6.5, that way they have optimal access to all there nutes. You should look into foxfarm oceanic forest at your local hydro spot, better then MG IMO.

i check my PH all the time and is usually between 6.4 amd 6.7 i have read online that it could be a calcium problem which i am not sure , thats what my plant looks like when u look at pictures with calcium problems again it seems to only affect the fan leafs mainly. I know it is not the water getting on the leafs and it magnifiying the light. i have started to use nutes and 1/4 strength 15-30-15 if it is a calcium problem what is a good thing to use? also i have notice a few little tiny flies around it here and there they are black not white which i think was probably the dirt but i killed most of them with my hands or vacum lol any help would be appreciated...........

If you think its just calcium some simple "cal mag" could do it, a lot of companies make this, I use botanicares. like $20 for a liter or $50 for a gallon at a hydro spot. I actually had the same thing myself just last week, but I usually give half veg, half flower nutes last week of veg, I didn't this time because I completely switched my nute lineup and my veg and flower nutes weren't the same so I was unsure of how much to give, but once I gave it the first full flower dose of nutes, it stopped.