sure i can explain. the 1000w mh (thanks for the correction) for my veg. room for my mama plants along with a few rows of floro's for clones. but the 400w hps are for the bloom room, i will be using like 4 of them and maybe a 1000w hps just to help out a little. this will be my first solo design, build and grow project. unless you got any input for me im gona try it this way.