Rust color spots on leaves

I have rust color spots that are spreading slowly on my plant. I grow dwc and run GH nutes and 1000 ppm. My humidity is around 50% and my water temp is 64. My air temp fluctuates between 72-77. For lighting I have 2 electric sky 180s at 12 inches from canopy. I thought it my be a calmag problem so I upped the cal mag from 2 mils per gallon to 5 mils per gallon. The spots are only on top leaves closest to the lights. I am in my 4th week of flower. Could it be a lighting issue? Any and all help will be appreciated. Thanks in advance

May I ask if you’re waiting for something to make those spots disappear? You’ve addressed the situation. Has new spotting appeared since? How long has it been since you gave cal mag?

I believe you are on to something hotrod. I think I am just overthinking things. This is only my 4th grow and I have been fortunate to not have any issues with my first three. Thank you for taking the time to reply. Much appreciated.

Looks like magnesium deficiency to me. Foilar feeding can work wonders for fast corrections.

Ok. Do you have any recommendations on what foilar treatment to use. thank you for the help. Much appreciated

Use your calmag at around 0.4 ec no need to ph and a good sprayer with fine mist.

Arkos said:

Use your calmag at around 0.4 ec no need to ph and a good sprayer with fine mist.

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This ^^. Be sure to get the undersides of the leaves as well. As fine a mist as possible. Either right at lights on or at lights off.

Ok will do. Thank you guys for the info. I am very thankful for your help

Skillcraft said:

Ok will do. Thank you guys for the info. I am very thankful for your help

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Im having the same issue. Did the foliar spray work?

Yes the spray worked. I did as instructed above and it corrected my problems. Good luck and happy growing.

Skillcraft said:

Yes the spray worked. I did as instructed above and it corrected my problems. Good luck and happy growing.

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Thx same to you bro