I thought i would post this to possibly help others. I've now had 2x coralife 9 or 13 watt twist sterilizers. Both have failed in the exact same way, i noticed that the little sightglass was no longet glowing so i thought that the bulb was blowm. Opened up the bulb compartment and it was full of rusty water. Somehow the seal between the glass and the plastic end is failing on these. It also seems like inside where the water flows there is also a chrome plated reflector-this cant be good for the water. Im now researching another sterilizer, just thought it would be good to post my experiemce to hopefully help someone else.