If its a digital ballast it should burn MH and HPS from my understanding. Also 175W is for MH bulbs, 150w is for HPS. Here's some options to buy both of these sizes of bulbs..
hey thanks guys...yeah its 175 hps for sure, the store where i bought it said he had a ton but sold out, i found them once online but then shut my computer and didnt mark the site, right now im running 150 bulbs in them which work good