400w HPS or 600w HPS?

[imatool666]

im growing in a 4'x4'x6.5' grow tent. i currently have four plants doing very well under a flourecent light in veg state. In a few weeks i start flowering, now what would be idea for my 4 lovely ladies, 400w hps or 600 hps given my tent size?

[tinytoon]

depends on your cooling capabilities. My tent is the same size and run a 400w with no probs what so ever but with a larger volume fan for the lamp I could prob run a 600w

[iGrow27]

I agree that if you can exhaust the hot air, a 600 Watt is the better option. Also to consider, NextGen digital ballasts work for 400 and 600 watts in either MH or HPS for about $280. That will give you additional versatility.

[Deejay2163]

A 400 watt would probably do just fine and be much less problematic to vent.In that space , a 400 watt HPS should do just fine. The heat differential will be worth it in my opinion.