tent question 8 lemon skunk clones

Hi gardeners,I'm not a complete newb but I am when it comes to what I'm trying now. I've 8 lemon skunks in soil,in 18ltr pots. I'm vegging with a 600w dual spec in a 1.2sq tent. I want to know if it will be safe to hang another 400hps up when its time to flower? I have a 6inch extraction fan aswell

And how do I post pics please?

Having the two lights in there will jack up the heat quite a bit, so that's your primary concern.

How to post pics? Above the area you're posting in, there are a series of icons (beginning on the left with font stylization icons). The third icon from the right (a green box with a little tree) is the one you want to click to upload pics.

-spek

Yeah the heats what I'm worried about but its not too hot with 600 running. I just want lots of bud. I used 10ltr pots before with 600w and struggled to get ova an oz