Freshwater Clams Care: Lifespan, Size, Food, Tank Mates

Freshwater Clams aren’t the most popular type of pets for aquariums. But, you might see Asian Gold Clams for sale at your local pet store or when shopping for fish online. Freshwater clams are easy to care for, so long as you know what you’re doing. If you want to add a few to your fish tank, here’s everything you need to know about caring for freshwater clams.


Freshwater clams grow to one or two inches in size (the shell). There are instances of clams growing bigger than two inches. The shells of freshwater clams look thick and have a ridged surface on the outside.

Freshwater Shell Size, Texture & Color
Freshwater Shell Size, Texture & Color

The shells of freshwater clams are usually a shade of brown. It ranges from light to dark brown. Some clam shells have darker strikes of color. Others can have streaks of white. Often, algae grow on the clam’s shell.

To best care for freshwater clams, you need an aquarium that’s at least 20-gallons. Freshwater clams need a medium to a very fine substrate as they like to burrow and cover themselves. Sometimes, you can only a small part of the shell and their siphon.

Water Conditions

Keep freshwater clams in a nitrogen-cycled aquarium that already has an established ecosystem. Water parameters should be:

  • Aquarium pH: 7.0 – 8.0
  • Water Temperature: 70 – 80 degrees Fahrenheit
  • Lighting: Simple tank lighting

Ammonia and nitrites levels should be 0 ppm. Run tests to make sure that nitrate levels are standard as well. Freshwater clams depend on calcium to build strong and healthy shells. You can test the water for calcium and add supplements if needed. Be careful when using plant fertilizers and medications. Some ingredients can kill clams. For example, copper, even a little bit, can kill freshwater clams.

The aquariums must have enough water to provide nutrients to freshwater clams—the bigger the fish tank, the better for the freshwater clam or any aquatic animal. But, be careful not to overstock your tank. Every fish, shrimp, or clam that you add to the aquarium adds to the bioload.

Smaller tanks like a 10-gallon tank cannot properly process the bioload when overstocked. You can also add better equipment to larger tanks. For example, a filter to help if there is too much waste in the water column.

Clams prefer oxygenated and slow-moving water. A steady stream of moving water allows clams to filter food from the water column better. If the water moves too fast, then the freshwater clams won’t be able to capture enough food to survive, and they die. An excellent spot to keep clams is under the power filter return where the water in the tank is always moving.


Freshwater clams help keep the tank water clean by eating uneaten food and detritus. These bivalves usually bury themselves in the substrate but they do move about from time to time. They eat using siphons.

Water comes into the clam through the incurrent siphon and leaves through the excurrent siphon. The clam remains buried in sediment and sticks the siphons up into the water above so that it can suck in and spit out water. The water that the clam sucks in through the incurrent siphon contains oxygen and food.

Clam Dissection

Though the clams can get food from the water column, you need to supplement their diet with fish flakes or pellets high in calcium. They also like to algae, so some algae wafers are also suitable for supplementing their diets. Try to keep clams in semi-planted tanks or tanks with lots of plants. Freshwater clams will eat falling plant matter from live aquarium plants.

Clams eat by filtering food floating in the water using their siphon. But, do not overfeed your clams as this can cause issues with the water quality. It’s always a good idea to have testing kits for ammonia on hand to check the water condition.


Freshwater clams can live for six months or more. But, how long they live for depends on the tank conditions. For instance, the shift from the store to your tank at home can cause your freshwater clam to die if it does not acclimate to the new environment.

If you do get to keep clams, you have to check the water quality more often to ensure that all is well. Things to look out for are spikes in ammonia, dead tank mates, cloudy or foul-smelling tank water. All these are signs that the clam may be dead or dying.

Tank Mates For Freshwater Clams

Freshwater clams are calm and non-aggressive animals. They are filter-feeders which means that they get their food from the water column. Never house freshwater clams with any fish that eat invertebrates like freshwater puffers. Here are some peaceful freshwater clam tank mates:


Freshwater Clams can also do well with snails such as:



Things To Consider

Choosing Healthy Clams

Freshwater clams usually rest on the aquarium’s bottom with their shell somewhat open or closed. An open clam shell should reveal some of its inner tissues. These tissues are usually off-white or pink. An open freshwater clam shell should not be more than slightly open.

If it is somewhat open, you should see some of the inner tissues. If the freshwater clam’s shell is wide open or you can’t see the internal tissues when it is slightly open, then the clam is likely sick, dying, or already dead. Healthy freshwater clams react to movements. So, if you try to touch its shell, you should see it move a bit, or it may slam the shell shut. Healthy freshwater clams should not have shells with cracks, holes, or other deformations.


Sometimes, when freshwater clams don’t acclimate to their new tank, they die. You need to remove the clam’s dead body before it affects the water quality. For instance, it can cause ammonia spikes, which can then kill tank mates. Always check on clams as they may die while buried in the substrate.