And if so then yes it's most likely due to the switch. Not much to worry about. Raise the light more if it continues and acclimate it to the light slowly. It looks very minimal I wouldn't worry so much.
It looks to me you have defoliated this plant to the point it's fighting you back. I don't pull fan leaves like people seem to love to do. It needs leaves to take in light to grow buds logic of photosynthesis. But its a method I used to do so I understand why.
I would suggest a phosphorus is locking out your nitrogen. This could be due to too much nutrients or just too much phosphorus. Are you using hard water cause that only makes this happen faster. I'd suggest get some distilled water and use a nute that's nkp is close to 3-1-2 ratio. This should...
what is your choice of nutrients, i suggest if your new to all this start with a complete one part nutrient. that way you know its got a good blend of what it needs.
example; dwc 3gal in a 5gal bucket. change every 3 days.
or lets say a 40gal rez under one light change every 2 weeks unless they are super feeding then maybe as soon as 1 week changes.
it will give you worry free growning
Use hydroguard at 2 mil a gal. and a pinch of pond-zyme with barley you'll find it at pet store that sells fish. ever since iv made the switch my temps can hit the low 80's and iv had no prob nice white roots. happy plants.
its because soil is a buffer. its hit its holding capacity and now is locking out the nutes from your roots. im sure your new water is full of minerals and that is the culprit. or maybey its lacking cal mag. i dunno. but im sure its hard water if they are happy then not all of a sudden. its just...
soil is a amazing buffer that i only use once in a while anymore. i love me some fast hydro. and my buds get so heavy and huge. its a hard jump to make i dont condone it to everyone.
lol and you may have to supplement calcium and the magnesium as well. i know its complicating things but i think thats all you will have to change if you've always had good results. dont start over if youv done well in the past. just look at what has changed. and if its just water then, ro and...
my suggestion is your probably going to have to look into getting a reverse osmosis filtration system for the ladies. untill then you may have to buy ro water at the local food mart.