Hello again dear friends. I think you know the deal by now, I will post a question and will give karma to all who play. All senior reefers will give karma to the first person who not only answers the question but is most complete. Each week’s question is posted with years of experience to play. Tonight's question is of medium difficulty so I will increase the years of experience to 3 – if you have 3 years experience or less you are eligible to answer the question. I am glad to say, I leave for vacation early tomorrow morning but I will be logged online tomorrow afternoon to see how the thread develops and respond. Once again, this is posted in General since its all in the name of fun as well as education. Enjoy.... Please see the picture below (credit’s to be given tomorrow). Please tell us what is on this heater and what caused it. The heater has been in use in a reef tank and working well all the while, about 12 months or so.