Yellowing and leaf tips curling down

Problem: Yellowing of leaves, tips turning down, and a little droopy.

Question: Think it's a heat issue? Get up to 85 sometimes for a few hours during the day but usually stays 75-80. Also is it possible to let them finish in 2.75 gal pots or need to transplant before flower?

Info: Budget Gro II 600w HPS. Big ones (bagseed from pog kush and lemon kush) are 4 weeks old and clones (white widow x g13 and chemdog) are 1.5. Bigs were transplanted 2.5 weeks ago into ff ocean and have had no nutes since. Humidity 45-55%. Big plants pots are 2.75 gal clones are in 3.25 gal. Being watered with 6.0ish well water. Lightly pruned 4 days ago but problem has been happening for 2 weeks. Trimming the yellow part off when they take more than 1/2 the leaf. They are dark green. Although they are having this minor issue they are growing like weeds =)

First post here although I have read an enormous amount from this and other forums. Hope the info is enough! Thanks in advance!!!!!

1st pic look at bottom middle, 2nd middle, and 3rd is just to show set up

From what I have read is that Oceans Forest should last you 30 days from the day you place your plant in it without any nutes, 2.75 gal is small are you restricted in your grow area? The bigger the pot = the bigger the plant = the bigger the yield. If you dont want your plants to be very tall then you are fine , and as far as temp. I would say stick to 74 degrees if you can, make sure you dont have stagnant air. You want your leaves to lightly flutter. Get a fan on them if you dont have one. Test the water you are using also , and one last thing it is easier to help if you have pics

Wow your pics just came up when I pressed reply, check this pic out View attachment 2501010

the larger plants def. look like they are suffering from heat exposure, you want cool air blowing on your plants

Heat is not the problem. They look a little over watered to me.

Got an exhaust fan on top of the closet, a fan pushing air towards the exhaust fan and a fan blowing on the cool tube and plants. During the day it's opened up for lots of fresh air and put an oscillating fan outside the doors. Don't know how much more can be done to keep down temps without spending too much $.
How often/much would you recommend watering with this size pots? Usually wait until the outside ring of the container is bone dry down to the 2nd knuckle and add a big powerade bottle.
Thanks again!

Just came across the idea that the fan on the cool tube and plants constantly could be drying out the leaves. Any opinions on this?