[surfdad_grows]

For a gallon and mine is the same it came to 3-3.5 ml to get me to 6.5. I know the pain. And I’m using GH ph down. I started using the RO water from the machine at the grocery store. The 2nd 5gal your ph will be perfect before nutes. I test my 5gals before using them.

[jmystro]

How are you measuring pH? Digital meters will lie at some point. They don’t last long even with proper care. 400 ppm is fairly hard but there’s much worse out there. You may want to filter it a bit to get it under 300. It will be difficult to maintain an acidic pH with high calcium (alkaline) water. Cheap pH down would mainly consist of citric acid. Phosphoric acid cost more but is more stable and becomes plant available dihydrogen phosphate. Most pH down products contain some ratio of the two.

[sensimillashane]

I’ve switched to using “Mendocino Honey”

for my ph down. Has molasses honey and glucose.the 3 needed sugars, Works great !

then I add recharge and/or great white for the microbes which help with not needing to ph so much. Do that every feed on top of grow dots filled soil and I haven’t had one problem since this change.