question on HPS bulbs and MH bulbs

Question on which ballast (MH ballast or HPS ballast) can function properly using MH or HPS bulbs interchanged? help is greatly appreciated.. will save me some cash

get the ballast that can support both lights

this is called a digital switchable mh/hps ballast

Or You Can Get A Conversion Bulb It Goes From Mh Ballast To Hps Or Vice Versa!!!

Best -> Dual-spectrum (both bulbs at the same time) - EXPENSIVE
Next Best -> switchable ballast (both bulbs at different times) - PERFECT FOR GROWING
Least Best -> Single Ballast w/Conversion bulbs (this is least best - or worse option cause conversion bulbs are far less effective than regular bulbs.) - ONLY IF YOU HAVE TO

DO NOT attempt to use an MH bulb in an HPS ballast (regardless of wattage) or vice versa it is a fire hazard.

i have a switchable sun system ballast, it has a lil switch for changing between MH and HPS. it was by far the most expensive piece of my grow though, buy it online to save money.

thats whatsup thanks for the help... i kno i heard that u wouldnt have to buy two seperate ballasts but i jus wanted to make sure which ones work with both HPS and MH

chronicle.. how much did u end up paying for yours?

i heard of people using hsp ballists with Mh bulbs of the same wattage