Droopy leaves and [h problem

[0MEGA]

today when i looked at my plants they looked a bit droopy, and one is yellowing a bit which i am assuming might be a n def its around 3 weeks and i havnt fed it because it didnt look like it needed it, and the ones i did feed with 1/4 strength had burn at 2 weeks.
should i cut off the yellowing leaves and the ones that rusted, its the bottom growth first couple pair of leaves. and i water once every 2 days with RO water.
new growth looks good just a bit droopy too. plants are 3 weeks old and 2 including the one thats yellowing at 2.5 weeks old
my temps and humidity have also been a bit wacky latley
85 during the day with 20-30 humidity how can i raise more humidity?

 

[J52058]

Grab a humidifier About 30$

 

[GroHi]

Your temps are too high... primary issue I can see w the plants, though they also appear hungry for the P. The drooping & leaf fringe stand-up are heat... primarily. The larger center fan in pic 3 is P... I'm pretty sure.

Not knowing what you're growing in, e.g., soil or coir or brand, I'd say you need to feed them... mix your solution/pH it/drench the whole pot till you get 30-50% run-off. Then back off a little

The heat needs to be lower... they look to want the 78-80F. If you're reading 85F, is that an average? I'm guessing it's peaking in the higher 80's...?

I wouldn't worry about the humidifier... good luck keeping it in the 20-30's for much longer. I'd love to have that issue! Peace brother.