How much space are we talking? and how big are you trying to get them? Id say in a 3 by 3 space, and doing sea of green method, you might just pull it off...but anything bigger then that and your going to encounter some problems. if I were you, Id go for the 400, or maybe even a 600, dude, believe me you will love yourself for it. I always say if your going to do it, do it all the say, dont half ass it. Get the 400 or 600 and enjoy.