What do you find you need to do differently?IMO 400w Max in a 3x3 tent.. I'm surprised you can get that warm under a 250w LED. If you can lower the temp a bit it will help.. Growing under LED is not the same as HID. You will go through a learning curve.. I'm going through this myself. What made my plants happy under HID isn't doing the same under LED. I have to learn new habits and stop my old ones. NOT EASY after so many decades using HID.
Everything.What do you find you need to do differently?
Two questions:Some plants will stack calyxs and foxtail until they run short of Nitrogen. Heat also encourages it.
VG