Just wanted to post to save someone else the heartache that I have now. I just put a new timer on my metal halides when I was forced out of town by work. When I came home, the timer hadn't turned the lights off and my tank was basically a boiling pot for a seafood gumbo. So hopefully someone can learn by my mistake, ALWAYS TEST THE TIMER! I won't make the same mistake again. I lost 6 finger leathers, a green leather, all my mushrooms and riccordia, most of the livestock, and the rest of the corals are pretty bad off. After only 28 hours with the metal halides on and me not watching the tank had gone from 80 to 92 degrees. Please don't let this happen to you.