[pogodzib]

Yes, there are people that have had some success with keeping bi-halves in sumps for filtering their water, but I wouldn't do it because of their nutrient needs, temperature requirements, and how fast they dissolve, hence contaminating the water, once they die. Both the food requirements and reef tank temps cause them to generally only survive a few months, at most Add that to the fact that you need to feed them to keep them alive, then how much good are they really doing if you want to keep them in order to clean the water since you're actually adding more food into the tank in order to keep them. Refugiums with macro algae work good with less problems. The main 4 types of clams that people keep in their reef tanks not only get their food from filtering water, but also from light. If you still want to try to keep them, make sure that you do plenty of research about them and talk to people on reef forums that have kept them.