I disagree here.. if your towards the end of your grow DO NOT add Nitrogen or anything but maybe molasses or if you want to be organic, sucanat as a sugar/carbo.. Nitrogen is a mobile element and as you flush and remove salts the plant will steal from the bottom first.. if you have more then 2wks to go, yeah, add a bit more to your nute regimen.. but a proper flushing will cause the plant to use it's mobile elements and thus causes crazy coloring in leaf's and Nitrogen is always taken from the bottom of the plant 1st.. so early on in a grow a great way to tell your plant needs more N.. And remember with the drain holes.. sometimes it's not a matter of how many holes you drill if they are tiny.. enlarge them buggars. And what do you use in the base of your plants to assure your soil doesn't clump up and block the holes.. one of my secrets, Styrofoam from packing I get in products versus tossing it.. it's light and works awesome..