I have been reading as well and I think it is heat. I can leave my hand under the lights but the room is hot. The humidity is 40% or less. The water temp runs around 75 but the room temp can and does go up to 90. I have a fan blowing and even used it to blow heat out of the room for two days. It will be cool the rest of the week so that will help.
I will do an 8 step recovery anyhow and possible buy another fan. I just hope this crop gets done sooner then later before it gets tooooooo hot. I have two small fans that I can use in the mean while and that might be enough.
I will keep you posted. Thank you brother.
A few suggestions:
You got to get that water temp down.
Place styrafoam cups (or any container) full of water on the lid and all around the tank.
Roll up old rags, faceclothes or old clothing like a cigar and soak them and lay them on the lid.
Place two boards under the tank so air gets under it.
Get the water pump out if it is still in there.
Make sure the air pumps are not near a HOT light pumping hot air into the tanks.
Be sure the lights do not shine on the tank or lid.
Have lots of air circulation, but do not have the fans blowing directly on the plants too strongly. Oscilating fans are best.
When you add water to the tank, add cool water.
When you go to 12/12, let the lights be on at night if possible and off during the day, IF possible.