I've got everything kicking around to start up a planted tank again except a tank and lights. I've got CO2, substrate, nitrate, yadda yadda.

What I'm wondering is for a 45g (36Lx12Wx24H) will a dual bulb tek light be enough? I work at an LFS and the tek light retrofits work out quite cheap for me. Or would I need to go with 4 bulbs.

Oh and how clean can you get flourite? Can you get it actually clean or will it allways have loads of dust in it? I've only cleaned it in buckets, never used a collinder or the likes.