Help, plant leaves browning

Hi all. Here's what's happening thus far: I had a small bug problem (fungus gnats I believe, they came with these clones [Can anyone verify that this is a gnat, picture below] ) and I tried a few remedies of which little helped. I read somewhere to let the plant dry out a bit more than usual to help off the pests. I let the plant sit a day longer than I usually would before feeding to dry it and the leaves started to go upwards like how a Christmas tree looks when it's tied up; I assumed it was a bit dry and it was normal and proceeded to feed/foliar feed it. About 2 days later the plant looked similar (although a bit more healthy than when it was dried out) but some of the leaves have started to brown in the middle.

Plant/grow info: Medi-Juana strain, Pro-mix organic soil, 1000w HPS 24/0, 4'x4' grow tent, Floranova Grow nutes, oscillating fan inside, using distilled h2o.

My thoughts of the cause of the problem:
- A bit off pH maybe? I have been pH adjusting (testing not with a pen but the drops, so it could be a bit off where it should be at)
- I don't have an intake in the tent, I have some flaps open on it to help with fresh air but nothing induced into it

Any ideas guys?

Thanks in advance

How hot does it get in their?
Looks like pH slightly alittle with the sides being discolored.

Mid 70's. It's in a basement that is kept cold. I'm getting a real pH pen this week to see if that helps. Assuming it is a pH issue, how long should it take to recover once fixed?

Idk.. I dont thinks its pH.

whole plant shot........the full Monty

scroglodyte said:

whole plant shot........the full Monty

Click to expand...

What do you think it is?
Maybe (Zn)..

Pic of the whole plant is what he needs.

scroglodyte said:

whole plant shot........the full Monty

Click to expand...

Nice Ol Bud said:

How hot does it get in their?
Looks like pH slightly alittle with the sides being discolored.

Click to expand...

Wow! Was I a bit off temperature wise... I just put a thermometer in there, it was low 90's. I've since opened up the tent, put an air purifier in front of it and am hoping for the best. I'm going to try to get a fan and ductwork for the lights tomorrow. Do my plants show signs of heat exhaustion? If so, will they recover?

Flush that mother fucker. Lol.
Its nuti-fryed.

What's the ratio of water to pot size you're supposed to do for flushing? I just gave them 1 gallon (they're in 1gal pots filled about 3/4 the way up with soil) each of distilled h2o. The runoff looked real nutrient-rich.

Also, I got the temps lowered to low 80's. Over a 10 degree drop so far, between that and the flush man do they look better already!