Rusting leaves - what could be the cause?

Can anyone guess what’s going on? Here is how I’m growing

White widow Auto
Plant is about 38 days from when she popped out of the soil
2x2 tent
HLG 135 Rspec
3 gal with FFOF on edge and FFHF in the middle
Humidity around 50%
Temp 75-80

Just fed her (Bergmans) for the first time this weekend when I noticed the first set of leaves in the lower middle turning rust color. Now she’s shot up and leaves on that top tier are also turning.


Did you adjust the pH of your water food mix?
How much did you feed it?
It looks more like a pH issue to me.


Yes I adjusted to ph before I mixed the food in and after. The ph was 6.04

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You only need to adjust it after mixing the food.
6.8 is where you want the pH for soil.
You are not far off but might be low enough to lock out a couple minerals.
Next feeding maybe mix enough to flush out the soil a little bit. Water until you get about 25% drainage and then remove it and check ppms and pH of the run off.
I would suggest just feed 1/2 strength for now. The Ocean Forest should still have some nutrients in it.


I feel like the ppms are way too high. It was 1477. Ph was 6.12

This is today

It appears like classic potassium deficiency.

It tends to start out looking like nute burn and progresses to a point that the leaves are crisp and brittle.

It also looks a bit like she’s heavy on nitrogen. I think continuing to water to a generous runoff, and feeding a flower time food going forward is the right move.

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They seem to be getting worse