lighting Q regarding using hps and halide bulbs with a certain ballast ??

hi all,

I have a 150w ballast that runs a 150w metal halide ( its the lid off a D+D aquarium ), I want to use this to veg and then change the bulb for a HPS bulb..

now the ballast states it will run either MH or HPS but im unsure on how to go about it, the unit takes RX7 double ended bulbs.. all the HPS ive seen are screw ends

do I just change the fitting? or is there something im missing ?

il post a pic of the unit and ballast asap.. I just wanted to get the ball rolling so to speak

cheers

hopefully the pic of the ballast has been uploaded

more pics of ballast

so im guessing the end of the lead that's goes into the light hood with the rx7 fittings could be simply changed to hps screw fitting?

I don't see anything on the ballast to switch between modes ?

guessing if I use a 150w hps bulb it shouldn't overload the ballast.. and I know its not ideal but would a 150w hps and maybe a cfl flower bulb be ok for the flowering stage, room is 1.2x1.2x2.0 approx