Maybe its blight? And other things...a problem grow

I'm on my second grow with LEDs (Mars-Hydro "Mars II" 1600 watt) in a 5x5 tent in the basement. Just a week out from harvest and it hasn't gone well--which is also to say that I should have posted a week or two ago, but things have been crazy. Ugh.


The most critical thing is that I think I may have fungal blight--it seemed the closest thing from a few books I have, but not sure. Pictures below.


But as background, as the plants moved into flowering they started to get really droopy. At least some did--I'm growing a few different strains and there's variation. Maybe it's because I let them veg too long (6 weeks), but that doesn't seem too likely. My first grow was with Mars II 1200 watt and they did not get droopy like this at all. This time, a few of the plants (9 in all) required a six or eight stakes, with ties, to keep them mostly vertical. I've had a fan blowing lightly on them all along. General Organics fertilizer. Three drench treatments, watering, with Azamax to nip some mites in the bud.


But then the (fungus?) hit, two weeks ago, maybe a little less. First thing I noticed was bright yellow, looked like a quickly spreading growth, on one of the buds, but then after that it was almost entirely leaves. (I cut that piece of bud out, and have also taken off the worst leaves.) In regular light, though, the leaves look less yellow, really a mixture of yellow and brown. The leaves also get very dry and crumbly when they are discolored. The buds are also pretty sparse on a few of the plants with the most leaf damage, but it seems like bud formation would have been way before the leaves had problems--but maybe still related?


I think I've treated these the same as my first grow, which was disappointing in terms of yield (6 oz. with 1200 watt LED) but still I think reasonable for first grow. I may have let the humidity get a little higher with this one, into the low 50s at times, maybe even high 50s a few times, but I've brought it down close to 40 recently thinking that might help possible fungus problem.


I'm wondering if I may have not watered them enough. There were two times the leaves got droopy from too long between waterings. I read that you should let the top 2" dry out, and also that it's really important to have plenty of oxygen for the roots, but wonder if I let those top 2" get too dry, and so underneath also.


And the last thing...oy, embarrassing!...is that twice in the last week I left lights on overnight. Once the grow light (messed up the timer, long story...) and once I just left the regular light in the room on. After each of those times, finding the light on in the morning, I kept them dark until the following morning. I checked around online and got the sense that this is not fatal, but today I noticed several little blips of bright green that I'm pretty sure are new vegetation growth. Will the buds still mature over the next week--really only five-ish days now.


Lastly, while the leaves are most problematic, if it's fungus, might this affect the buds themselves in terms of quality?


Oh, and really lastly, I do not have outside ventilation to the basement. It's a big basement, and with the LEDs it doesn't get too hot. I think that should all be okay, but someone recently said it's important to get "fresh air" to them. I'm not sure exactly why that would be, but maybe?

I'll post a picture of leaves, and two of the plants, an angle that shows both the droopy problem, on the left, and the sparse bud problem, on the right, but having trouble getting a good picture under the grow light.


Oh: the smaller leaf on the left is a strain not so affected by the (fungus?) but has white spots and not so healthy looking. There are some spider mite eggs on the underside, but some are yellow-brown, I think because of the Azamax, and I can not find any live mites.



Thanks!

 

ok, thanks for the response. my thinking was that in a basement, where the concrete gives off CO2, and a large one, there would be enough CO2 for them to breathe, and that the dehumidifier would take care of that end of things. but...sounds like no.


what about bringing cold air in in the winter, especially with the LEDs, which don't give off much heat? i actually had to have a heater running in April even without ventilation, just to keep it above 60. how much air do you need to ventilate with, can it be kept small enough to not cool it down?