In theory, a nano tank is a marine aquarium 29 gallons and under. You will get alot of different opinions on this though. A nano can be a reef, but we nanoers needed a forum of our own because it can be harder to maintain a reef in the smaller tanks, or anything else for that matter. The "Reef Tanks" are usually pretty elaborate, and you get to use kalkwasser on those, I don't think you could do that very well with a nano
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Wow, that 12G is looking good Chris. How is that anenome handling it?
BTW, I couldn't find the nudibranch.
Clint