Bro, whatever you do.. do not go by FF guide included in their trio and online.. theyβre insanely high amounts even for photos. Iβd listen to these guys as far as if your in decent soil wait several weeks to feed.. probably around the time you start seeing flowering signs.
Back to the nutes tho, when I used FF I basically used only Tiger and Big Bloom in flower because the soil contains enough to get thru veg. When it comes time to feed, the Big bloom is much less potent and you could probably do 10-15 ml per gallon.. the Tiger bloom is much more potent and Iβd start around 5ml per gallon probably. Iβd aim for around 5-600ppm your first feeds.
FYI Iβve noticed the Tiger bloom drops pH significantly so keep an eye on that. Good luck