High PH

[kevin.n]

I'm using promix with 35% perlite. Using chemical nutes (advanced nutrients).

My problem is I can not keep the PH down. Water with well water (91 PPM) at a PH of 6.7. Add nutes at 6.3. But run off after watering is in the 7.3 range. Tested some new soil to see if the promix was acidic, but it measured 6.7 ph (same as water). Still in veg so I haven't used much nutes so that shouldn't be the problem. Tried flushing one out and a week later PH is back up. Takes about 3 days to dry out between waterings.

Also plants leaves are yellowing. Problem is working its way up plant. New growth looks fine and then tips start to roll under.

Any ideas or solutions, thanks.

My best
Kevin

 

[Droopy Dog]

Wow! That's strange. I'm always preaching about adding powdered dolomite lime (pH 7.0), to peat based mixes like promix because it is so acidic. I would still suggest it.

Garden Sulfur will lower pH, but I've never used it or needed to, so you're on your own there.

The only thing I can figure is the AN nutes, but I have never used them either, running Earth Juice and assorted meals in a mix of my own, very similar to promix.

DD

 

[bongtastic]

Probably a pH issue. First thing, get a different pH tester to compare with. You could have 3 different pH testers all giving you different readings.

Like DD said, I think powdered lime will still help because it keeps the soil in the sweet spot and is a great buffer.

Leaves rolling down = overferting
Yellow leaves usually means a deficiency in nitrogen. What does this mean together? Probably a nutrient lockout due to pH.