The temp had been a little high at first around 32c now it's at 29c. so I thought maybe this was because of heat, is that the case? I have cervante's book, didn't find anything but when looking online this looked like heat problems. Could it be circulation probs too? the plants are on a 17gal plastic tub it has 4pc fans, 1 intake 1 exhaust and 2 for circulation. the intake and exhaust though I have them with holes, like the ones on a pc case. maybe I need more fans or just cut completely the openings for the fans? the entire thing is covered with mylar on the inside. help appreciated
32C is definitely getting too hot. Did you start the plants in those containers? How often have you watered them? Usually when plants are small you keep them in small containers or you will end up drowning them because the soil will stay saturated for a very long time because the roots don't reach very far or use a lot of water yet, yellowing can be a sign of over watering. You can carefully use larger pots top start plants but you have to be careful when watering to only water like the middle area of the pot and not too much or the bottom will be saturated. When the soil stays wet for a long time it keeps air out of the soil and suffocates the roots, and you can also get root rot. If the leaves look/feel thick and puffed up that is usually a sign of too much water.
They look pretty good to me- just a little bit yellow. The may need a dose of dilute nutrients As mentioned do be careful not to over water. I use a soil tester that you place in the plant dirt to measure moisture. It's come in handy as it reaches 7 inches into the soil. Lots of time the soil feels dry on the top two or three inchs, but seven inches deep there is plenty of moisture. I would overwater without my tester. The symptoms of both under and overwatering are the same, wilting, Good luck, please keep us posted.
Make sure your PH balance is right in your water ...so many growers skip the simple things and assume that because its weed, it will grow. The more care your plant receives the better it will turn out. Try to maintain a PH of between 6.0 and 7.0 Be careful of the over watering as well. You only need to water plants if top soil is beginning to dry or if leaves have gotten stiff and curved at the ends. The rest of watering would be done with a spray bottle to substitute for natural rain ..the whole plant needs water not just the roots With some correcting and a close eye you'll be fine