I'm really starting to understand this PH/PPM thing.I've notice that when I top off or make new solution,My ph starts at about 5.4.It drops to 4.6-4.7 everytime.Ro Water,Cal-Mag,flower food.So now I decided to start the ph at 6.1 and see if I will end up with 5.2.I won't know until I check tonight when it will be "daytime" .I use regular hydro flower food,it's a powder.What are the advantages of the 3-part fert compared to the kind I use?what other suppliments should I buy during my flowering phase?