Best size containers?

[milwaukee]

hey folks, I'm just finishing up a grow room (4x4x7) and am going to be getting some MP5K seeds, a short plant good for stealth grows. I'm having second thoughts about my chosen containers though. I was going to use 5 gallon buckets, but I'm thinking the following:
1. Takes up too much space
2. holds too much soil for proper and quick dry time thus introducing root rot conditions
3. Quite pricey to fill five gallon buckets with soil.

Can I go down to a 2-3 gallon container?
I've seen it said tht a 3 gal is fine for most plants- what size do you use?

[astro]

I've heard as a general rule, one gallon per foot of height. So, I guess it depends on how large your plants are going to be. I like to grow fewer plants, but grow them tall. Some like to grow a lot of plants and flower them out when they're a foot tall. So if you want 5 foot beauties, you probably want 5 gallon buckets. But for 2-4 foot plants 5 gallons might be overkill. Just remember to put some holes in the buckets for water drainage.