yea you can place lights where ever just so they are eveny spread.. you wont need side lighting since your doing scrog.. 81 would pry be fine how far away from lights is thermometer? once they start flowering the bud will be in the light i had slight issues so the lower the better but leave enough room under screen to get ur hand under there to tuck leaves and bend.. the buds can basically almost be touching the cfl with no problem so no worries.. i had 1 burnt bud before tho.. if your runnin 81 with 20 id just cut to 16 max during last 4-5 weeks of flowering.. start with mayb 8 1st week of flower to ease into transition then up to 16 by the 3rd week or so.. ved u dont need much at all mayb 4-6 lights.. start lights mayb around 10" above seedling then move to around 4-6" away.. u will tell if they are stretching for light lower it if they are drying up crisping or showing sign of heat stress raise um up a little bit..
