Hi thanks for the reply, 3x5 out of the 8x5 is my veg/clone room/chamber...and that will be covered using growking 6400k CFL's , I do know about the speed controllers availible...but was sceptical about weather they worked...My first responce is that you have about 40 sq. ft. of growing space, but you only have about 12 sq. ft. worth of lights (@ 50 watts/sq. ft.). 600 watts divided by 40 sq. ft. is only 15 watts/sq. ft. - that ain't much!
Secondly, get a ceiling fan speed control instead of a "dimmer switch". They look very similar, but are intended for two seperate purposes. They are usually sold in the same area of the store.