Switching MH to HPS during grow

Hey,

I'm looking for some advice regarding what time between veg/harvest it is best to switch from MH lamp to HPS lamp?

Switch immediately upon going to 12/12 or continue with the MH for a while?

Specifically, I've got a sunmaster bulb that I've had nice success with on full grows. My ballast is digital and can use either, so I got an HPS and I'm wonderin what point in the grow to switch the bulbs.

Any help is appreciated!

Thx...

great question i added rep + hmm anyone out there help him out

I always switch bulbs when the photoperiod changes.

im auctually testing this out between some ladies as we speak. just for the stretch of flower. ill let ya know in a week or 2.

Im thinking about doing the same thing myself, I'll be interested in seeing your results.

im not entirely sure but the 2 bagseeds seem to have a diference of about 5% in height gained. seems as though the MH has keept the plant down some. in the future when i start flowering i will be keeping the MH as the main lighting and suplementing with some CFLs for the cooler light spectrium. only untill the stretch is over. goodtimez

M/H veg 18hrs ,then one week prior to changeing to flower,change to 24HRS useing M/H,Then change to 12/12 hr cycle and it will flower quicker due to lack of darkness ..........pot will put a last ditch effort to grow as big as possible in the first 2weeks after changeing to 12/12 as it prepares to repoduce and flower.....then change to HPS bulb till harvest.

i wouldnt go suggesting that. some sativa strains are prone to hermie (not experienced this only heard). goodluck with flipping there world upside down with the lighting change.