I use fox farm trio and I dnt need ph but it also depends on the type of water and the temp of the water I use well water at 72 degrees and my ph just with nutes is 6.4 everytime, but u will need some sort of pH down/up when u flush ur system or if ur soil is a high ph u will need to have lower ph water to balance ur soil out. Also w.e soil u end up useing make sure to use something to areogate ur soil ur roots need oxygen the more the better, I use perlight. If u use ur 5gal bucket like I do drill a shit ton of holes around the side and the bottom or ur roots wount get enough oxygen