Have a look at this, new one for me..

This is showing up on bigger, older, leaves 4wks into bloom. Starting as faint rusty color and slowly gets more rusty spots starting. Fresh promix mp with fox farm conditioner top dress. Gh 3 part flora at 3-2-1. Ph 6.3 mid 70’s temps 60% humidity. Any help appreciated.

Hold on

Your top dressing with one brand
And using the GH flora trio also

BobThe420Builder said:

Hold on

Your top dressing with one brand
And using the GH flora trio also

Click to expand...

So too much?

Yup

If you want a better answer give more info, how much soil? room temps? are you doing anything else you haven't mentioned?

Did some digging since over feeding didn’t fit. No burnt tips is the first clue and why I wasn’t convinced. Leaves tell the story, I know I’m gonna get slammed but I’m no newbee guys, been doin it 24/7 for 20+ years. Look at this pic of calcium dif.

I never said it was over feeding

But doing multiple things gives you no control over your plant..thus the issues

Your leaf doesn't look like the example you show of mg def and that's exactly what mg def looks like. People get it wrong here every time. Golden yellow spotting is what it first looks like. Your leaf looks different so why you put that mg def up I don't know as it isn't the same appearance. I suspect you're over feeding, but you didn't give additional info.