Ph in run off is low

just received ph meter that was ordered. tested water in, ph was 7.0. run off was 4.5. what needs to be done now.

When I received my pH meter it was way off and had to be adjusted, I would suggest that you check it
-good luck

will do, thanks

7.0 is too high, you want around 6.5 in soil 5.8 in Hydro as a general rule

My runoff is usually 5.8 @ 6.5 in. With runoff as low as yours I would be expecting to see Leaf burn excetera. if you’re pretty sure your meter is not off you might consider a flush to correct issues and stop and/or prevent damage ?

Will try calibrating first and test again

If your pH meter is calibrated correctly, and your root zone pH is that low I would recommend you flush your plant with 6.5 pH water to correct the problem before it gets worse. While your flushing, take occasional readings from the run off water. Watch to see that it’s coming back up to 6.5 where you want it to be.


A low 4.5 would make me suspect over watering and possible root issue a flush may not be best choice how often are you watering are you waiting for soil to dry judging by weight or finger in soil? Also agree check meter first but may want to re-pot
how big is plant and pot? could also be sign of being root bound
a flush may only be a temp solution depending on cause of the ph swing :slight_smile:

Tried flushing today. Adjusted ph in to 6.7 and run off was 5.3. Not certain if I was supposed to do this, but I tried again with tap water at 9.4 and run off was 5.6. You may be correct about being root bound. My plant is 24" in a 2 gallon pot. It’s in a SCROG so kind of difficult to re-pot. My first grow and not certain what strain it is. Was given seeds. Thank you for your input.

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Wish I could offer a better suggestion but aside from giving roots more space you will simply have to roll with it she will still produce. Every plant we grow is a lesson take what you learn from this one and apply it to the next you need to flower small if you use smaller pot 3 gal is my min I typically use 5 gal for soil

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managed to remove scrog and got plant into a 3 gallon pot. watered plant for a day to settle new soil and waited two days before watering again. roots were root bound, a little yellow but at least no smell. tried in tap water of 9.4 ph and early run off was 6.4. will wait 2 days until next watering and try same thing to see if ph stabilizes. in ph of 9.4 and check runoff. does this procedure seem right?

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