Hello everyone! I have been out of town and upon returning to my beloved grow I have found some pretty nasty stuff. The plants should be receiving a foliar spay of HOCL every other day. What do you guys think is causing this and is there any alternative things I should be doing to stop, and also prevent it from happening again?
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Heya @codyjester . You said you were away for a bit. Has the environment been steady or has it been hot?
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I think you have Alternaria in that 1st photo, here is how to treat your plants and grow area.
Remove all the bad leaves and mist your plants with Hypochlorous Acid (HOCI) or Hydrogen Peroxide 3% (h2o2). Use the HOCI at full strength all over the plant, to include under the remaining leaves and spray down your grow area. It will spread like wild fire if you don’t! I spray just before lights out and haven’t had a problem with it. I have had Alternaria in a tent before, nasty crap if not treated asap. I have been told by other growers they fog their plants and tents several times, but with HOCI one heavy treatment will do the job. If you use Hydrogen Peroxide 3% (h2o2) 3% it takes 3 treatments over 3 days and will probably come back a few weeks later. Make sure you have good airflow and good exhaust, and keep your eye on temperature and humidity levels.
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I don’t quite understand this . Are you doing this? Or are you asking if you should be doing this. I would not be spraying the plants every other day. For the most part, this treatment is one and done. Not always, but mostly if done correctly.
What nacho said above is 100% correct. 
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So I have been generating my own HOCL at 440ppm. I have simple been doing a spray Monday, Wednesday, and Friday to try and prevent any outbreaks. I was out of town for a week and had a friend watching over things. Here are all my daytime averages that I have collected.
VEG
Temp: 76 F
RH: 60%
VPD: 1.2
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Could you please jump in here. Could use some clarification on how often these plants should be sprayed. As far as I know, you should not spray more than once a week. If you’re using table salt to make this, especially. The residue of salt on your leaves will kill your plant if it is excessive. Wait for Bob to chime in, but I imagine the best thing you could do for your plants right now (at lights out), is get a spray bottle with plain clean water. and spray them all. Get that salt off those leaves if that’s what you’re using. 
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Cody,
I see in picture #1 where @nacho151 is recognizing brown lesions with a yellow halo…(classic Alternaria infections). However, as I look at how the damage is progressing, I think there’s a lot more going on there.
If you still have the plant, look at the run-off EC and pH. What I notice, looking at your plants, is that the damage is PREDOMINANTLY concentrated on the leaf margins…which would be highly unusual for Alternaria. Certainly, Alternaria can easily infect weakened tissue but I highly suspect there was an underlying pH/EC condition that did the real damage.
Regarding use of your hypochlorous acid, I’m glad to see you can generate your own ! Hap is correct in that a single application of full strength HOCL @ 440 ppm should have easily killed the disease if it was there. I wouldn’t suggest repeated application of HOCL unless you’re under severe conditions (late fall bud rot pressure in outdoor plants).
There is some SODIUM in your HOCL obviously. Because HOCL is ‘surface active’ and not at all systemic, you’re not likely to see any ill effects IF you follow the formula directions.
You can ELIMINATE the sodium completely if you purchase some potassium chloride and substitute it for sodium chloride in EXACTLY the same weight/measure. Potassium chloride is fairly inexpensive online…
Hope this helps…Bob
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