Rusting / twisting of old fan leaves after topping

I'm currently using a 250w LED grow light with Fox Farm soil. No other added nutrients.

As water, I buy regular distilled water from the grocery store, which I have never had any issues with.

Week 5 of growing, everything was going perfectly. After I topped the plant at the 6th node, growth stunted for a few days as expected. Today, after going to check up on it, I came across these rusting spots on the older fan leaves.

The leaves themselves feel primarily healthy. Out of the few that I found, only one of them felt crunchy at the tips of the leaf.

I've never seen this before in any of my grows using the same set up and am curious to know if anybody else has seen anything like this.

I've removed the bad fan leaves from the plant now.
Pics attached.

Any help is appreciated! Thank you!
<3

Calcium deficiency. Spotting. Wrinkly texture. But nitrogen excess. You’re using distilled water why?

hotrodharley said:

Calcium deficiency. Spotting. Wrinkly texture. But nitrogen excess. You’re using distilled water why?

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I was thinking possibly the same.
What would cause either?
I read a while back that it was the best you could get because of the pH balance, without actually buying chemicals to balance it out yourself. Ive used it since on sativa strains with no issue

Corruptionz said:

I was thinking possibly the same.
What would cause either?
I read a while back that it was the best you could get because of the pH balance, without actually buying chemicals to balance it out yourself.

Click to expand...

Distilled water would have a pH of 7 but the pH should be measured after the nutes are added.

Corruptionz said:

I was thinking possibly the same.
What would cause either?
I read a while back that it was the best you could get because of the pH balance, without actually buying chemicals to balance it out yourself. Ive used it since on sativa strains with no issue

Click to expand...

That’s hard to believe but I wasn’t there. There’s no calcium. No magnesium. So you have to add cal mag. Forget distilled. Get it out of the tap in kitchen.

hotrodharley said:

That’s hard to believe but I wasn’t there. There’s no calcium. No magnesium. So you have to add cal mag. Forget distilled. Get it out of the tap in kitchen.

Click to expand...

I'll get some calmag tomorrow and will kill the distilled water immediately! Will report back in a week. Thanks!

Why did you cut off the leaves?

xtsho said:

Why did you cut off the leaves?

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I cut off the fan leaves for 2 reasons
1. They needed to go. I just topped it and there is plenty of other new growth to compensate for it.
2. I didnt want to risk having an infection spread to the rest of the plant. In my experience, it happens very quickly.

Thoughts?