i got 9 plants in a 4x4 tray hydro setup in 1-400 wat hps , i know i need more light but how much is it going to affect my yield ?? also do you think i should surround the hps with some cfl ??
Yield dependes on more than light like, nutes,temp,humidity,type of plant. I would have bought a 600 watt hps for max growth. If you use cfl for side lighting it will provide more growth.