I wouldn't put pots right on the floor in my basement because the concrete stays about 50 degree F or so and conducts heat well.  I put two shelving units together to create a 4'x4' footprint grow tower that goes floor to ceiling.  I hung 3 shop lights on each shelf and 3 more off the floor joists above the tower to create 5 grow levels that each take 6 standard trays.  Because the basement is cool in winter I bought 5 of those metalized mylar emergency blankets they sell in the camping section of the store for about $2 each...one for each level of the tower.  I lay them over the three shop lights on each level and they're big enough that they hang down over the edgesand create a zone that is a bit warmer and has more light for the plants due to their mirror like surface reflecting light and heat back to the plants.  This helps hold in the extra heat from the ballasts that my plants really appreciate down there in the basement.  This set up isn't good for very tall plants, but I can start as many as 1000 plants in a 4x4 space.  The lights are on timers set for 16 hours.  All I have to do is water once a week.