So seems like alot of people use 20/4. have never tried it...but I am willing to try if it is worth it. Have always done 24, and to be honest they dont stretch...but the first 2 weeks seem really slow from seed on 24. Wanna speed up the veg time this time, dont have much room, so need to weed out the dudes asap. So maybe 20/4 will be the way? Does it seem to effect male to female ratio at all? Thanks