I have 2. A 29 gallon freshwater community tank in my Daughters Nursery. It is the BEST thinng we have put in her room. The soft light and the gentle sound of running water have magical sleeping powers on her. She has slept for 8 hours per night with out interuption since 3 weeks old. For those of you with babies, you know how amazing that is. I attribute it to the fish! I also have a 40 gallon stretch hex reef tank in my office. That's my hobby tank, and I really enjoy it.