This article will help intermediate aquarists decide if keeping clams in a reef tank is right for them.

Clams are not for everyone, but in the proper environment, they can easily become the centerpiece of a reef aquarium. With a reputation as being hard-to-keep, however, some hobbyists are afraid to take the plunge. While most clams are not appropriate for the beginning aquarist, the reality is that a little knowledge can go a long way toward success.

Who Should Keep Clams?

Serious hobbyists. Clams are not really for casual fanciers of saltwater tanks or for people using an aquarium as decor only. Keeping clams successfully has a lot to do with maintaining water quality, and the aquarist who is involved with monitoring his or her tank on a daily basis will have the most success.

Anybody with a fish-only tank with non-standard filtration and normal output lighting would also want to steer clear of clams. In most cases, the fish in a fish-only aquarium may nip at or eat various invertebrates, including clams. Further, clams need higher levels of calcium than are found in most fish-only systems.

Filtration Equipment for Clams

The clam-ready aquarium will need standard filtration. By standard, I mean an aquarium that has, at a minimum, a protein skimmer and live rock or other means of providing robust biological filtration. The filtration system for a tank housing clams should be sump-based. Sump-based filtration provides added water volume, which assists with overall stability, and it makes it easy to run sump-based filtration devices such as a large protein skimmer, reverse flow substrate reactors and dosing equipment.

Lighting and Flow: Two Important Reef Aquarium Parameters

Light and flow are two very important considerations for all reef aquarists, and the individual considering a clam is no different. There are many types of clams, and not all require the same lighting needs. It’s a myth that all clams need high-intensity lighting. For instance, two of my favorite clam species—crocea and maxima clams—need more light than others. While Gigas and derasa clams can get by in deeper tanks (14 inches or more) or under power compacts or T5 lighting, the crocea and maxima clams do best under high-intensity, reef-ready lights. The more colorful the clam, the more light it requires.

In terms of flow, Martin reminds aquarists that clams are filter feeders. They rely on the water flow in the aquarium to bring them food. Too much flow, however, can cause the clam to become irritated and not open. As with most things in this hobby, it’s a balancing act. Be sure there is good flow, but also avoid blasting the clam with current. Observing the clam’s behavior will be the aquarists’ best guide.

Clams Make a Reef Tank More Stable

One of the best things about clams, is that, in addition to the outrageous colors and intrinsic beauty of these animals, the clam itself removes nitrates from the water. Clams are constantly filtering the aquarium water, meaning that a tank with one or more clams can be a more stable and healthy environment. I’m not suggesting to go out and buy a clam as a quick fix for a nitrate problem, but clams can help a well-functioning reef function even better.


My name is James, and I’m in love with aquariums and fish since I was 12 years old. Back then my dad gave me a goldfish, and it’s been 35 years learning about this fascinating hobby. I’ve had some freshwater aquariums, tried my hand with marine tanks for 10 years, and kept some reefs for a while too. Here in the website I try to share some of my knowledge and experiences on fish keeping.


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