Works well on a traditional sump By Old Salt on 2/17/2014Old Salt would recommend this product to a friendI had the Innovative Marine suction cup refugium light. It worked well, but every once in a while the suction cup would let go and the light would fall into the water. So I got this one and it works well. It's a little strange having it on the side of the sump (hence the 4 stars) instead of extending over it. But it is bright and grows the macro algae well. Most important it is really secure.