lighting question

I am using a 400mh in a 4x4 grow tent now.I have 9 plants in 3 gallon pots going,using fim and LST methods.I want to get more light so my buddy gave me another 400 watt HPS.Temps run about 77 but as soon as I started the other light they went up to 85 before i shut it off,I really want to flower with 2 400 hps.Question has anyone else ever done this and what are max high temps,any other suggestion would help

those temps are higher than prefered, but still ok. my highest is 3-4 degrees above you and my girls are doing woderfully!

If you have solid air circulation you can run both the lights. I wouldn't let it get hotter than 85, that is your max average temps at. In the fall/winter it is easier to do it. I know someone who once had 2x600watt hps in a 4x4 tent intaking cold air in the winter.

If it levels off at 85 you're fine. You can always just try circulating more air through your tent - I'm assuming you don't have ventable hoods. Could always get sealed hoods as well.

what if i try raising the lights up farther,they are about 18 inches away now

your still in a tent, it needs to ventilate the heat.