It's true but other factors can effect this too. It can lower or raise from plant giving off waste salts. 5.2 to 5.8 is best. Shurely you must have a pool or pet store that has dropper kit to check PH. They are cheap and mind you the color of the GH 3 parts will change the color but you will be much closer than guessing. It's not worth playing with and it can hold you dead still till it's fixed. Get a small kit till you get a PH pen.
LOC NAR1958 Reviewed by LOC NAR1958 on . growing hydro with no way of checking ph i know i should have waited to get the ph pen but i couldnt. i know that ph should be aroung 5.5 -6.0 in hydro. everything is looking good but im kinda nervous cuz i dont want to lose my babies.i heard that ro water is 6.0 then when you add the gh 3 part form.the ph will drop to around 5.8.is this true. Rating: 5