I don't think its safe to run a MH bulb in a ballast specified for HPS. You can do so with CMH retrofit bulbs, but its not safe with normal MH.Put a MH bulb in your HPS ballast for veg and run both. Then when in flower put the HPS back in and run both MH and HPS at the same time. If in containers you can rotate your plants under each bulb for a even amount of trichs on each plant. Yes MH boosts the trich levels just a bit.