This stuff is pretty potent and burns the young transplants nothing too bad just use good water PH'd water for the first 30 days thats what I do. Its the best soil I have ever used.
I have never used fox farm but i should think that a name like fox should have everthing it that is needed,but if it does not have perlite in then def add some won't hurt..tyke.........
more perlite is always a good thing as much as you can afford.
PS: you can recycle perlite by dumping your old soil in a tub of water, the stuff floats, you can skim it off and sterlize with bleach and re use it after the the chlorine has gassed off. (I use the micro wave for small batches.