New grow leaves light green and burnt

[Maloney73]

Hello everyone and I’m hoping you guys can help me. I was growing under a T5 Fluro and everything was going great, I then re potted the plants and put them under and adjustable digital ballast, had it on 400 but now 250. I thought the problems were down to the change in lights and all that went with it, temp went up to 28c and humidity dropped down into the 40%. But today I noticed one of the plants has burned leaves and all new growth is very light green and spindly, all the plants have spindly new growth but only that one has burning. Not to close to the light as it’s the smallest plant. Anyway it just occurred to me after re potting in bigger pots perhaps I’m overwatering and they are suffering from a deficiency, or some other nutrient problem since re potting. I didn’t even think and watered like crazy thinking they would be fine. Anyway to cut it short I really have no idea what I have done !! If it’s from the change in lights and temp/humidity or I have caused it after re potting and watering. Any help will be greatly appreciated many thanks

[D.A.A.S.69]

Are you checking ph?
New growth pretty much always looks a lighter color, for a few days, then it's changes to a healthy color green.

[Maloney73]

Yeah I have been checking ph but it’s in coco so might be slightly to high. The nutrients have a ph balance in them but I have read we should still check. Just the new growth looks spindly and the one plant has burnt. Hope I haven’t killed them

[Treetrunk]

Try raising the light a bit. The plants will need a couple of days to get used to the more powerful light.

[Treetrunk]

Try raising the light a bit. The plants will need a couple of days to get used to the more powerful light.

The serration on the leaves is probably caused by too much light.
Get yourself a cheap lux meter and take the guess work out.
I've just got new QBs and was nuking my plants. Spent £20 on a lux meter and no more deep fried plants.👍

[gbauto]

Perhaps it's from your environmental conditions.
The temps in the tent are a bit high for HID lighting and the low RH creates a high VPD at the leaf surface.
What that means is the leaf is trying to transpire so much water through its surface, the plant's vascular system can't keep up.
I think lowering the temps and raising the RH to get a suitable VPD that the plant will tolerate.