What is causing this discoloration??

So I fed them their first dose of flowering nutes 2 days ago and have been battling high temps for the past 2 days also. The discoloration is brown in color and has started at the middle to the top of the plant and is only occurring in one of them. They all were watered with the same water. Is this a deficiency or a burn?
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Looks like a Cal-Mag issue.. what nutes and soil do you use? Check the pH of the runoff to be sure the soil is stabelizing the pH when you feed/water-- if it is way off- adjust the pH of the nute solution/water every time you use it...

add some Cal-Mag to your mix- but instead of waiting until their next feed- give it in their mid-week water... It is probably a problem that was already well underway before you fed them, since the visual sign AND the signs that it is fixed take 3-7 days to show....

Good Luck! ;0

Thank you so much for the response. They are in FFoF and I am using the FF trio (big bloom, tiger bloom, and grow big). I will make sure to check my run off next watering. Shouldn't it be something like only a drop by 1 on fun off? And also what could I get locally for cal mag, could I just use Epsom salt temporarily till I can get some cal mag ordered. Also here is a picture with some different lighting
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how long have they been in the soil before you gave them nutes?

Just over 6 weeks. This isn't their first time receiving nutes but the first time receiving all flower nutes

Epsom salts are the mag part of cal-mag.

And is this leaning more towards looking like a mag def.? Cause if so I could grab that for watering them tomorrow.

So it has been like 3 days since I watered them with 1 tbsp of epsom salt to 1 gal of water. They looked to be improving for a day but looks like the problem is becoming worse. Here is an updated pic of the discoloration.

That looks like a mag deficiency if watering with epson salts and not seeing an improvement check the pH of your runoff. ... also there is a sticky for diagnosing plant problems and you will see a pic there that looks just like your plant. Its under the magnesium part of the post

NiigataOp said:

That looks like a mag deficiency if watering with epson salts and not seeing an improvement check the pH of your runoff. ... also there is a sticky for diagnosing plant problems and you will see a pic there that looks just like your plant. Its under the magnesium part of the post

Click to expand...

Would I just be looking for my runoff to be around the drop in 1 ph or do I want a drop of about .5 ph

and while you're reading that other sticky you can check out all the other stickys that the wonderful people here know their shit and have some wonderful reading and kill some time while your waiting for your plants to grow