I would say that is a ph or feed issue not light burn do you have a ph meter if not you definitely need to get one ro water take everything out of it so you will have to supplement the calcium and other minerals. I seem to always get a weird one to were every body looks good till you get that one that makes you say what the hell. I have flushed and used comeback from fox farm and good results with it. Your nitrogen may be higher in this cup to with the worm casting probably just enough to make it act funny but im not 100% sure on that. Everything thing else looking really good though
Just a little nitrogen toxicity, the leaves are starting to claw. Probably just the hot soil you’re in. Give her a few more weeks, and if she doesn’t straighten out, you can flush her. I’m betting she will be just fine, just keep an eye on her. @AAA
Okay 80 ppm out of the RO and it’s 9+ PH…
Drinking water federal standards.
TDS level as follows: excellent, less than 300 mg/L; good, between 300 and 600 mg/L; fair, between 600 and 900 mg/L; poor, between 900 and 1200 mg/L; and unacceptable, greater than 1200 mg/L
pH isn’t a quality that falls under EPA regulation because it’s considered an aesthetic quality of water. However, the agency recommends that municipal drinking water suppliers keep their water supply at a pH of 6.5 to 8.5.
It’s not really a pH of 9. RO water and distilled water are too clean to get an accurate pH reading from, and it will always read high with pure water. You can add some pH down (just a few drops and it will likely drop way down into the 5’s) and then start adding pH up to bring it back up to a proper range. Mostly what you are doing is adding substance to the water for the pH meter to read.
I prefer to speed this process up a bit by adding 1 part tap water to 3 parts RO water - then there is already something for the pH meter to read and I spend less time adjusting.