I'm at a loss. Backup would be nice.

I have about 12 seeds started under a T5HO. I have 2 fans on it, and a osci fan blowing.

They're at week 3, they all look good. aside from the top leaves curling up, like heat stress.

ALl the plants look like they're "heat stressed"

Temp in the room is 72F/80% Humidity.

The lamp is about 6 inches from the plants (optimal growth can be achieved between 1in-18in)

I've been playing with distances. but nothing seems to work.

No nutes, PH'd water, FoxFarm Soil,

I would take a pic, but my camera's LCD screen cracked :/

Try reducing your air flow? One fan's enough for several plants, like a dozen, IMO.

Move the fans around, and move the lights up to 10inches maybe?
Good luck.

Ill try that, the only fan that has direct contact wtih the plants is the osci fan.

the other intake fans bring air from my garage to cool the fixture. I can usually get my plants to grow withing .5in with this method in the past.

This is just very unusual to see, same seeds i've been using and all