Heat/Light Stress

Hi ladies and gentlemen, havent been on for a while. First grow this year, I have 2 plants on the go, a Speed bud auto and another auto that i cant remember the name of, theres about 2-3weeks between starting each seed. Every thing started fine and the same as the other grows I have done with the same set up. My temp usually runs a little hot 30-34'c, thats with a fresh air intake straight from out side and exhaust fan, a fan blowing direcrly under the hps and a fan blowing on the plants. im on a mission this year to get it sorted, im waiting on a (hopefully) better exhaust fan to arrive in the post.

My grow space is 1.5' x 1.5' x 5'8
250w hps (bulb changed 2 grows ago)

This year i added the fan under the hps and found i could get the light 6-8inches away from the 3 week old speed bud. After a day r 2 the leave started to get signs of heat stress (leaves cupping upwards) so i moved the light to around 2 foot away, the cupping stoped but the leaves then started to go yellow from the middle of the leaf out, starting with the oldest leaves working its way up. The palnt went into flower 2weeks ago and there hadnt been much bud growth and now bud growth seems to have stopped altogether. Is the early damage still effecting the plant now or am i still getting heat/light stress.? The light is 2 foot above the plants, i have a lux meter bought and waiting on that to arrive also. By the way i have never had this much problems growing photos in the same space

Pictures would really help.
The yellowing could be heat damage or a Cal / Mag issue.
Seeing the plant will help diagnose the problem.
And it is way too hot 30C = 86 degrees
What is your RH ?

When lights are on the RH is around 20, this is the first grow where i am measuring the RH.

Heres a pic of the yellowing, it seems to have stoped now and is only on these few leaves,


And this is the second one, its around 2-4weeks old, kinda small dont you think.?


Im still having problem with slow growth, what could be the main cause f this.?

I may be wrong, but from what It appears like in the pot with the smaller plant is that the soil is too dry. When your soil pulls away from the sides of the pot, it needs water. As for the flowering plant, what is your nute strength? If it is too low it will pull what it needs from the leaves (specially in flower) causing yellowing like that -but since it isnt doing that on the newer leaves it was most likely a temporary stress and is on its way back to good times

With the smaller pot, it does look a bit dry in the pic but on my soil mister meter it says that 3inch down into the soil its still pretty wet, as far a nutes for the flowering plant, its getting pure tap water, the soil i started it in was way to hot so i flushed for a coupe of waterings and havent given any nutes since

after these 2 plantsare finished im going back to my trusted Ice from Nirvana

looks like some other weird shit is growing in there from pic 2, defiantly looks like the plant is suffering have you checked the EC of the run off its either looking for food or getting burnt by to much

ha yeah never mind what else is growing in the pots, its homemade soil that my gf's father made, it was all that was on hand at the time, i dont have any equipmnt for checking the EC of the run off, i've never had to bother before