I know first hand what foil can do and if you like slow growth and droopy plants, go ahead and use it, 81 isnt too hot either, but no telling what his temps are either... the ones i had under foil turned male so maybe i had bad luck
FOIL = BAD can you say heat stress? switch to mylar or white paint
USE distilled water tap water has crap in it
The MG soil he has is pure shit and has no perlite in it( sorry no offense) read the ingridients, also chemical ferts effect taste in the end so its best to use organics...
also...