Using General Hydroponics pH Up/Down and I'm having to use massive amounts to get my pH down to 5.5-6.0 range. I mean like literally 1/12th of the bottle to do this for one tank, I've stopped leveling pH until I get this solved because I'm afraid I could damage my plant by putting so much in. I'm using filtered water from my fridge right now which normally sits at 7.5 and goes up to 8.5 after putting nutes in. I have this same problem with pH down when also using distilled water/nutes. Any help would be appreciated!