Need Help! Question about water runoff

I have a small grow tent and 400w hps. I will be using soil and 5 gallon buckets with drainage holes at the bottom. When I water the plants and its starts to drain out of the bottom of the pots, how do I combat that extra runoff? Wont it be a problem if I have water sitting at the bottom of my tent?
Or should I just water so that there is only a tiny bit of runoff? and would that be enough water for the plants?

If you are watering them right this run off should be sucked back up within a half hour, if not mop the excess up. You can pick up a drip tray fairly cheaply in your local diy/hydro store.

cool, thanks for help!