plants are struggling

ok let me start with my set up.im using my down stairs 6ft in height and 4ft by width room,ive got a small window with a vent leading to outside that i open atleast twice aday.im using a 400 wat hps.im growing orange bud which i started out from seeds.I started with the wet paper towl which worked great to start them off. Now my problem started when i planted them in pea pots in a propagator the side started to show signs of mold after 1 wk, so i took the brave step an repot them into bigger pots.as you can see from my pics sumthing is not right.As for humidity and ph of water i dnt no cause my water here is fine and was i told to leave it standing in a bowl for atleast 24-48 hrs and my humidity is ok cause of such a small space an a outside window...any help will do !

If ur getting signs of mold ure not venting enough, ur RH should be high and by the looks of it the temp should be high aswell, get decent VENTILATION...also ALLWAYS pH the water anything below 6.3 or above 6.8 and u´ll be looking at probable nute lock up....check the charts in my sig

They look like they are doing ok to me. Still very young give em' some time.

my temp does rech higher than 30c (86f) which ive been told higher than then im in trouble.Getting an extractor is something i cant afford at the moment,so i need to open my window more often ?

I'm pretty new to growing as well, but Iv'e read enough threads on this site and as well as how well my plants are doing and that fresh air definitely makes a difference. I open my closet door and give em' 6 to 8 yrs of fresh air a day. Can't afford the fans, rewire and all. Opening the window will surely make a difference. The can't get CO2 sucking in stale air. I would also recommened getting that temp down. 84 is high. Try to keep them between 70 and 80. I bought a digital thermometer and try and keep em' right in the middle. If u don't have the funds get some kind of thermometer near them. 84 is too high.