Rust Spots/Leaf curling upwards

Hey guys this is a Tangerine Dream Autoflower. Basically overnight I noticed that on some of these fan leaves up top there is some rust colored spots/speckling and some leaf tips and edges are curling upwards. It literally did not look like this last night. My temps did get a bit colder than usually last night, dropped to about 65 F.

It is 9 weeks old, here's some specs:

3 gallon pot
Fox Farms Ocean Forest Soil
RO water PH'd to 6.5
CalMag used approx 3ml to 5ml (150-250ppm)
Nutes are FF Grow Big and Tiger Bloom (been very light on the nutes)

I'm worried this is a rust fungus as I don't want it to spread to other plants. I've been real light with the nutes only going as far as 1/2 strength more recently with the Tiger Bloom. Would it be bad to remove these affected leaves or should I wait and see what happens? Thanks guys!!

You must have the instant five minute dying plant disease...JK
You over did it on the Nitrogen and I think it will get worse before it gets better

Herb & Suds said:

You must have the instant five minute dying plant disease...JK
You over did it on the Nitrogen and I think it will get worse before it gets better

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My last two waterings were with just CalMag, could the Nitrogen just have built up from past feedings?

LOL I've been babying these plants for so long I kinda started to panic. So you don't think this is a fungus issue? Thanks for the help also

erebos said:

My last two waterings were with just CalMag, could the Nitrogen just have built up from past feedings?

LOL I've been babying these plants for so long I kinda started to panic. So you don't think this is a fungus issue? Thanks for the help also

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Nah grow it out but lay off the Nutrients a few weeks