the combination of a lowe's 5-gallon bucket and the ufo light inside it is almost completely perfect, because it's almost completely efficient. all that dense light inside that small space is unbelievably bright. it hits the plant from all sides, not just the top, because the inside is covered w/ reflective tape.
i have scrapped the idea of the aluminum-foil covered bathtub because too much light is lost in there. for flowering i may need to buy another ufo if i want good results, but that's 2 months from now. the 5-gallon bucket will be inadequate before long, if i start getting lateral growth, which is my goal.
there's only one downside to the ufo-in-bucket: air ventilation is a little low, and temps are a little high. i have a fix for that though: drill out many holes in the bottom of the bucket, and elevate it an inch or 2 off the floor. if that's still too warm, i'll just buy a budget fanthat i can situate flat on the floor, and stick the bucket right ontop of it, with its vent holes i just described.
from the start, ultra-low budget was part of my goal and still is. keep it simple, stupid. seems to be working great so far.
misc: mixed up some 280ppm food for usage starting tonight. if it has side effects i'll water it back down. also, haven't really used the 20"x24" mirrors but they'll come in handy in the flowering stage. i'm a big believer in light multiplication from a single source inside a small area; just place 2 mirrors facing each other and shine a laser pointer in there. you get shitloads of light from that tiny little laser. of course incoherent light scatters more than a laser, but confining it in the bucket works great. this is the principle i'll be using all the way to harvest instead of pricey/fragile/energyhog CFL/HPS/whatever