Perfecto makes an awsome tank for sea horses. It's a 47G Column. 31 tall, 18 wide, 20 long. I purchased this tank for my pair of Erectus. They are still in the QT tank and it's cycling now. This is the tallest tank I could find. Unfortunately, with a tank this tall, I can't reach the bottom 6 inches to clean the glass. Never thought of that when I bought it. Because the tank is so deep, I have to have Metal halides on it so the macros in the bottom of the tank get enough light. The sea grasses require higher lighting than the regular macros. I can't wait 'till the Erectus are in this tank.