Anyone put seahorses in there refugium ? I had two in my biocube and they only lasted about two months and I am not really sure why they died.
This is usually a bad idea for several reasons. The flow through most refugiums is usually far too fast for seahorses. They need fairly calm water so they can catch food, since they are not powerful swimmers like most other fish. Also, unless you get a tropical seahorse species they also need cooler water than is typical of most reef systems.
Another big issue is feeding. Buying captive raised seahorses that are trained to eat mysis shrimp is highly recommended. These are not inexpensive. Wild seahorses are very difficult to coax into eating anything other than live food.
Dwarf seahorses are in a class by themselves, and require live food. Unless you are prepared to keep brine shrimp hatching cultures going all the time, consider another species. Keeping up with their feeding requirements is a tremendous amount of work.
All and all, it's best to set up a separate tank for seahorses. Usually it need not be too large.