Brows spots and yellowing.

I'm on 80/20 coco perlite and I often run into these issue leaves start to show brown spots. I've been feeding her GH trio, following their flowering schedule (week 5) + calmag (to and tap mix 100ppm plus 100-150 calmag) and keeping total ppm under 800, this issue started to show badly for the past week or so. Would anyone have an educated guess if this is caused by nutriet/pH, toxicity/lack of cal mag or poor watering? Always watered everyday and flushed her 4 days ago which seemed to have made it worse.

There is some mites spots, which I run treatment for.

Is that coco plain coco like Canna Coco or something with dry amendments like Coco Loco?
How many ml's of calmag, micro, grow, bloom are you using per gallon?
When you say you water every day, is that always with nutrients or are you doing some type of feed/water alternating schedule?

Canna Coco. No amendments. I measure cal mag by ppm so it doesn't go too crazy, but just under 1ml per L takes it to 250ppm. I am following GH schedule it's like 0.6 gro, 1.2 micro and 1.8ml/L bloom and yes daily fertigation.

Matjf7 said:

Canna Coco. No amendments. I measure cal mag by ppm so it doesn't go too crazy, but just under 1ml per L takes it to 250ppm. I am following GH schedule it's like 0.6 gro, 1.2 micro and 1.8ml/L bloom and yes daily fertigation.

Click to expand...

In daily+ fed coco with no amendments, measuring outflow EC/PPM when you're having an issue can give you some insight.

Depending on what's in your tap water (most will give you a breakdown on their website), you can probably cut the calmag by half and boost the 3-part a little more (0.7, 1.4, 2.1), and compare outflow PPM for a few days and adjust from there.

Make sure the mix is calmag, micro, grow, bloom, in that order, with the water stirred between adding each bottle.

Make sure you always get at least 10% runoff when fertigating - this pushes out the old salts and keeps the EC of the medium consistent.

Do not ever flush with plain water. This creates osmotic stress on the plant. If the plant has a lockout, you either flush with the PPM that you want the rhizosphere to be at and keep flushing with that full PPM mix until the PPM coming out the bottom is the same as what's going in at the top. Or if you want to save time/nutrients, you can flush at half the PPM until the outflow PPM lowers down to the PPM you desire (2x the inflow during flush). If you feed the correct EC, you will never need to flush, though.