Week 13, Fox Farms soil, dropping leaves and yellowing tips

[Menequadon1]

Strain: Afghan 90 (having problems), Deep Chunk (looking good)
Age: 13 weeks (Afghan) 12 weeks (Deep Chunk) both in veg
Indoor (2x4 Ac Infinity smart tent bought 2026)
Medium: Fox Farms Ocean forest and Happy Frog mixture 50/50
5 gallon fabric pots
Watering about once a week, whenever pots become light weight and dry
Water source: distiled water, adding 1.8ml calmag and Fox Farms Grow Big every other watering at 1/2 tsp, aboyt 6.4/6.6 pH
Light: light that came with the grow kit, idk the specific model
Temp/humidity: 75 deg f. 60% humidity give or take
Main issue with Afghan is that she is dropping leaves constantly, and they never turn dark green or get very big, and all of them have nutrient burn signs and the tips yellow out, and then the rest of the leaf dies or turns yellow, and falls off
Problem occurred after transplant around week eight roughly I don’t remember an exact date. In the beginning of the girl, I had just been using distilled water without anything added to it and it did not balance the pH and I put a good gallon through the pot after I transplanted Afghan, and then soon after that problems began.
So far I’ve tried to just water it more consistently with the pH around 6.4 and I add Calmag every watering to buffer the water and I add fox farms grow big every other watering at a quarter dose
also, deep chunk has been getting pretty much the same treatment and has showed very few problems. Next time I water Afghan, I will be collecting some runoff the test the contents.

 

[compostmike]

That Afghan looks like the root zone got knocked out of balance after transplant, not one clean deficiency. The burnt tips are why I wouldn't just feed harder, but at 13 weeks in a 5 gal Fox Farm mix she could also be running low if the runoff isn't hot. The runoff test is the right next move.

Catch the first runoff and check pH plus ppm/EC. If ppm is high, back off the Grow Big and CalMag for a watering or two and just run plain 6.4ish water, without trying to drown the pot. If ppm is low and pH is in range, then she probably needs a light balanced feed instead of mostly CalMag. If pH is way off, fix that slowly, because the damaged leaves won't come back either way and you'll be judging by the new growth.

Distilled water has no real buffer, and adding CalMag doesn't make it behave like normal soil water. Fox Farm soil plus bottled feed can swing on you in a fabric pot, especially with a plant that is less forgiving than the one beside it.

 

[Menequadon1]

That Afghan looks like the root zone got knocked out of balance after transplant, not one clean deficiency. The burnt tips are why I wouldn't just feed harder, but at 13 weeks in a 5 gal Fox Farm mix she could also be running low if the runoff isn't hot. The runoff test is the right next move.

Catch the first runoff and check pH plus ppm/EC. If ppm is high, back off the Grow Big and CalMag for a watering or two and just run plain 6.4ish water, without trying to drown the pot. If ppm is low and pH is in range, then she probably needs a light balanced feed instead of mostly CalMag. If pH is way off, fix that slowly, because the damaged leaves won't come back either way and you'll be judging by the new growth.

Distilled water has no real buffer, and adding CalMag doesn't make it behave like normal soil water. Fox Farm soil plus bottled feed can swing on you in a fabric pot, especially with a plant that is less forgiving than the one beside it.

Ok well thank you, so its a good plan to just water with plain distilled water at a pH of 6.4? Whenever the soil dries out that is. I’ll catch the runoff and measure whats in it with my pH and ppm tester.
Also in the case of the pH being way off, how do I fix it slowly? Through multiple waterings with a pH closer to what i want to bring the soil to?

 

[compostmike]

Ok well thank you, so its a good plan to just water with plain distilled water at a pH of 6.4? Whenever the soil dries out that is. I’ll catch the runoff and measure whats in it with my pH and ppm tester.
Also in the case of the pH being way off, how do I fix it slowly? Through multiple waterings with a pH closer to what i want to bring the soil to?

Plain 6.4 water is the right next move, yeah. I’d leave the Grow Big and CalMag out for this one so you can actually read what the pot is doing instead of adding more variables. Water slow, get a little runoff, then check both pH and ppm/EC.

If the runoff pH is off, don’t try to drag the whole pot back in one shot. If it comes out low, water the next couple rounds closer to 6.6-6.8. If it comes out high, stay more like 6.2-6.3. Small corrections, then let the pot dry back and watch the new growth. Running 8.0 water through a low-pH pot, or dumping a bunch through it every day, usually just stresses the roots harder.

The ppm number matters just as much. Low pH with high ppm points more toward salt buildup, so plain water and patience. Low ppm with pH in range means she may actually need a light feed after she settles. Those burnt leaves won’t heal, so judge it by whether the fresh tips stop frying.

 

[Menequadon1]

Plain 6.4 water is the right next move, yeah. I’d leave the Grow Big and CalMag out for this one so you can actually read what the pot is doing instead of adding more variables. Water slow, get a little runoff, then check both pH and ppm/EC.

If the runoff pH is off, don’t try to drag the whole pot back in one shot. If it comes out low, water the next couple rounds closer to 6.6-6.8. If it comes out high, stay more like 6.2-6.3. Small corrections, then let the pot dry back and watch the new growth. Running 8.0 water through a low-pH pot, or dumping a bunch through it every day, usually just stresses the roots harder.

The ppm number matters just as much. Low pH with high ppm points more toward salt buildup, so plain water and patience. Low ppm with pH in range means she may actually need a light feed after she settles. Those burnt leaves won’t heal, so judge it by whether the fresh tips stop frying.

Thank you for that advice, I’ll post my finding after the next water. Any advice for chunk? She seems to be doing good. She dropped some interior leaves after the last watering, but I just assume that’s because of how dense her foliage is and that inner stuff wasn’t getting enough light.