Hey all, this is my first grow, and I'm getting brown spots on my lower fan leaves. I'm 3.5 weeks into an indoor grow. New growth looks fine, and other than the spots, the plants look generally happy. No drooping, nice and green, no curling leaves, no chlorosis.
I've got it in a fabric pot with 2/3 ocean forest, 1/3 perlite, watering when it's dry a couple inches down, but before it starts drooping. I noticed the spots just as I was about to start feeding. Until today, I've given it plain tap water corrected to a ph of about 6.5. At the first feeding, I gave it water with a TDS of 850 ppm, and measured the runoff at 630 ppm, with a ph of 6.3. This is happening to three different plants. Two are the same age in the same size pot, one is younger and in a smaller pot.
Now my questions:
1. What do you think is causing the brown spots?
2. Is this obvious that it's some kind of deficiency? When I asked about it elsewhere, I was advised by someone that tds/ph measuring isn't useful, and is pushed by people who want to be seen as "gurus". I admit I have limited knowledge of this, but it sounds equivalent to saying "why do you need to check the temperature outside when you can just look and see how sunny it is?" The same person said that it's nutrient lockout caused by excess minerals, even though it happened on plain water. My gut tells me that can't be true, but I'd be happy to be proven wrong. TL;DR: tds/ph measurements can give you valuable data to help rule out certain conditions like nutrient lockout, right?
Thanks!
I've got it in a fabric pot with 2/3 ocean forest, 1/3 perlite, watering when it's dry a couple inches down, but before it starts drooping. I noticed the spots just as I was about to start feeding. Until today, I've given it plain tap water corrected to a ph of about 6.5. At the first feeding, I gave it water with a TDS of 850 ppm, and measured the runoff at 630 ppm, with a ph of 6.3. This is happening to three different plants. Two are the same age in the same size pot, one is younger and in a smaller pot.
Now my questions:
1. What do you think is causing the brown spots?
2. Is this obvious that it's some kind of deficiency? When I asked about it elsewhere, I was advised by someone that tds/ph measuring isn't useful, and is pushed by people who want to be seen as "gurus". I admit I have limited knowledge of this, but it sounds equivalent to saying "why do you need to check the temperature outside when you can just look and see how sunny it is?" The same person said that it's nutrient lockout caused by excess minerals, even though it happened on plain water. My gut tells me that can't be true, but I'd be happy to be proven wrong. TL;DR: tds/ph measurements can give you valuable data to help rule out certain conditions like nutrient lockout, right?
Thanks!
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