High pH lockout in coco - tips for reducing

crow34! said:

3500k with added 730nm at end of day.

Click to expand...

Calbrowno said:

Hi folks,

Experiencing some quite severe lockout issues in coco that seem to be associated with pH being too high.

I know people say that you'll end up having problems if you chase run off pH in coco, but for example I just ran a 5.5pH feed, atleast 20% to waste and the pH is reading at 6.5... Have been trying to correct this issue for some time to no avail, plants looking like absolute death and see a lot of contradicting information on the interwebs.

Firstly, how the hell do I get the pH down - should I keep watering at 5.5ish until it comes down, or I've seen some say that they water with around pH 4 until it gets back into a more acceptable range. And yes I have tried flushing, it seems that my tap water really wants to creep up in pH over time..


Any tips welcome and appreciated

Click to expand...

Calbrowno said:

This is another thing I always see contradicting information on. flush with plain water or very dilute feed?

Click to expand...

silverwolfalchemist said:

From what I understand normal ph water can fuck cation exchange for coco, so should always use low ec to flush. Would love hearing more on the science. Plus coco is inert so don't wanna keep fluctuating root zone ppm or pH. They'll take what they need and you can measure EC runoff to make sure it's lower than input, so you know they're eating. Also question for anyone, shouldn't pH be testing slightly lower then runoff, meaning you're sufficiently rinsing out excess salts etc?

Click to expand...

1212ham said:

Calbrowno hasn't been here since 2020. Straight water can leach cal & mag from coco. Common recommendations are that runoff shouldn't be more than .4-.6 ec over input. I don't check coco runoff ph, it fluctuates.
Cocoforcannabis.com

Click to expand...