You can find FF nutes on ebay or if you have a hydrostore in your area. I believe it says on the bottle whether its for soil or hydro. I cant remember and my lights are out so i cant go and check. As for when to use them, Its pretty much all up to you and your plants. If you buy MG soil chances are that itll have time released nutes already in it. Its on the bag. Im personally 16 days into flower and have not used any nutes. Im in FFOF and havent seen any deficiencies so far so ill go til i see some. Asking which nutes are better is kinda like asking if a ford or chevy is better. Its all on preference and youll get 100 different answers.