Soooo this plant has been suuuper healthy all its life.
Now in a new pot after a few days and some 6.5PH tap water with nutes and she is loosing a few leaves.
Why exactly is my question. Is the water full of lime?
Nitrogen Deficiency or Magnesium Deficiency IMO... Id check your pH runoff as well.
Example: nitrogen deficiency (the lower cannabis leaves turn yellow and fall off)? Looks good other then that leaf. Hope this helps.
Not seeing much of a problem and I wouldn't say it's the water the problem would have occurred sooner, It looks to be like that leave or area aren't receiving adequate light which will cause this it happens as the plant grows.