I use hortilux with my grows and all is simple and fine. Most major growers (20 Plants +) use just plain HPS for growing and flowering. You might be able to get better results from using first MH during veg then HPS for flower, but I love the one bulb fits all solution in the hortilux. My understanding is that the MH conversion bulbs do not use the maximum wattage provided by the HPS ballest. One bulb for one complete grow is geat.

BHG