i have a 400 hps, hortilux, but i cant tell from pics.bump, someone must know the difference between a MH and an HPS
I was given a 400W MH setup with a 360W HPS conversion bulb with magnetic ballast.
I have no idea which bulb is which. They look exactly the same, ecept one bulb has a small cirlcular metal piece on it..
Which is which??