If you're lighting is too weak to begin with, it won't help much, you may have to add more lighting. If you're just growing a few plants, go down to home depot or whatever, and get a few more CFLs.
im going to be growing 9 plants and using a 1000 watt light over the plants. a metal halide for veg and a hps for flowering and i wanted to hang 2 little 400 watt hps in between the plants to get better light to the lower levels. thats when i thought about putting something on the ground to reflect light back upwards
mylar is available at any hydro store (as already noted above in this thread) also at htgsupply.com
they have lots of great products for growing from soil & nutes to lights to mylar!
i paid $15 for a 25 ft roll i believe. its really not that much money. what i found out works great is getting those science fair project poster boards (that fold in 3) and cut mylar to fit the size of the board and use tape to keep it on there and surround your plants with it...thats what i did...it works great because the boards are only a few bucks each and its very portable (ie. i can put it around the plants to keep alot of the light in the grow area and its lightweight and easy to move when its time to water or trim etc.
im going to be growing 9 plants and using a 1000 watt light over the plants. a metal halide for veg and a hps for flowering and i wanted to hang 2 little 400 watt hps in between the plants to get better light to the lower levels. thats when i thought about putting something on the ground to reflect light back upwards
Painting the walls white is not "better" at all. Mylar reflects about 95% while white will refect 85-90%. Not much of a difference but no, white paint is NOT better. As for if you really need it with as much light as you have, probably not. The amount of light and light intensity should be enough to penetrate through the plants. Just thought I'd clear that up a bit.