Brownish/grey spots on leaves

I’ve currently got 5 plants on the go. All of them are different strains and they were all bag seeds except for one. They are all in 10 gal pots in ProMix BX general purpose soil. I don’t have a PH tester so I am not aware of the PH balance of the water. I’ve been giving them tap water with Fox Farms nutrients. I started the season off with Grow Big and am now using Tiger Bloom.

For the past several years I’ve experienced problems with spotting on my leaves during flowering and I still can’t figure it out. All through veg they always look as healthy as can be, no wilting, no discolouration just solid dark green. It seems I only experience these problems come flowering and as It gets closer to harvest the problems get worse. I’m pretty concerned at the moments about my girls health. I waterd them with a diluted solution of hydrogen peroxide (3%) and I did a foliar spray as well. I haven’t noticed the problem get any better.

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Most of that looks like lensing due to a water droplet sitting on the leaf and high intensity light is shining through.

You also appear to have had a PH departure at some point. If you haven’t yet you REALLY should invest in a digital PH meter: the single most important tool you will own. If you don’t PH your input liquid you WILL get in trouble. Promix is a media and requires you to provide all nutrients to the growing plant. You should use the FF “drain to waste” schedule for Promix and PH to 6.3 to 6.8.

The fact that you’ve had problems in flower before indicates there is something not going quite right. PH meter along with PH up and PH down will get you where you need to be.


Lensing would make sense, though I don’t foliar feed we have had a couple weeks of some crapy weather, it will rain breifly for a couple mins here and there and then the sun comes back out full strength so i can see how lensing would occur on my girls.

I have tested my tap water with a pool test strip a couple of times, it seemed to be between 5-6 but i never did anything to try and adjust the PH, you are right though I desperatly need to invest in a tester and PH solutions. definitely won’t be making these mistakes next season, thanks for the input !!!