A coversion bulb is one bulb that has both Mh and Hps light specs built into them. Instead of having to change rooms or setups each time you switch stage and bulbs, you just flick the switch to one or the other without moving or rewiring a bunch of crap.

They can tend to be expensive though. Search names like Hortilux, they have those kinds of bulbs.
Nochowderforyou Reviewed by Nochowderforyou on . lighting by the way what is the best all around lighting for growing good bud. thanks Rating: 5