u need to buy a ballast to power the vho bulbs, say u have a 40 watt bulb in there now. that means ur ballast is only able to power 40 watts. the vho bulbs are 110watts. so i would recomend the ice cap 660. there the best! u mite be able retro fit it in your light, but im not sure with the heat it mite melt? i retro fit 2x65 in my aga strip, i did put a fan on it to. the last one i did for my 29gal the plastic housing melted,wo a fan!!!!!