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How to Keep and Care for Freshwater Clams in Aquariums

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Jocelyn loves learning about different marine creatures. She has a Youtube channel where she creates instructional tropical fish videos.

Freshwater Clam Care

Freshwater Clam Care

Clams (bivalves) are wonderful additions to the aquarium. Contrary to popular belief, they are not difficult to keep successfully in a properly maintained and aged home aquarium.

What Do Clams Eat?

Clams are filter feeders, meaning they acquire life-sustaining nutrients by filtering the water around them. In most home aquariums, there are not enough proper suspended particles throughout the water in order to sustain the bivalve’s life. In cases such as these, the clams require supplemental feeding or they will starve.

Clams can survive for quite a while without food—it is an unfortunate fact that this aspect of their anatomy leads to their ultimate demise in the hands of inexperienced keepers. Their clams may live for several months until the day they are ultimately found dead. A dead clam is no laughing matter.

Problems That Occur When Clams Die

When a clam perishes in an aquarium, it will lead to a deadly ammonia spike that can quickly kill the other inhabitants of the tank. That is one downside of keeping clams and mussels in the home aquarium; they bury themselves in the substrate and are difficult to locate when dead. In a heavily planted tank, this can mean days of hard work tearing out and replanting uprooted plants. However, there is a way around this.

Using Containers to Make Clams Easy to Locate

To keep clams contained in the aquarium, place them in a single-serve applesauce container. Poke holes throughout the container to aid in water flow through the sand. Fill the containers with a fine substrate, such as sand. Three or four small clams can be housed per container. Larger clams may need a container to themselves; it depends entirely on their size.

When doing tank maintenance, it is advisable to remove the containers and dig the clams out. Dispose of any that are dead. Dead clams smell like rotting, fishy flesh. Clams that refuse to close their shells are dead, dying or injured. They should be watched carefully, preferably in a quarantine tank, until you observe them acting normally.

How Do You Know if a Clam Is Healthy?

Normal clams are quick to action. When the water is disturbed around and over them, they will close their shells. This is a natural defense mechanism and a good indication of health.

A well-fed clam will show visible growth over time. Measure each clam before adding it to the aquarium. Once or twice a month, remove them from their enclosures and measure again. If growth is happening and continues, the clams are feeding properly. No visible growth may mean they are starving. In the case of clams that are at their full size, time will tell if they are feeding. It is a good idea to have differing ages, as the growth of the juveniles can be used to judge whether or not the adults are feeding.

A Clam Is Not a True Filter

Freshwater clams do not clean their environment as many people claim. Though they are filter feeders, these creatures act more like animals rather than plants. They do not remove nitrate and ammonia. They add these chemicals to their enclosures. They are animals—not plants. Clams are sensitive to their environment, and ammonia can be particularly deadly.

What clams do remove quite efficiently are various forms of suspended algae. A grouping of a few small, heavily feeding clams can clear the water in a 5-gallon aquarium within hours. They also filter out tiny creatures from the water. In a sense, they are filterers, just not the kind many pet stores market them as; clams are filter feeders, not filters. You do have to keep up with tank maintenance when housing clams.

Questions & Answers

Question: Do clams open by themselves?

Answer: Yes.

Question: Do dead clams smell rotten?

Answer: Yes.

Question: My turtle got his toe stuck in my freshwater clam, how do I get it unstuck without hurting the clam?!

Answer: It should let the turtle go on its own.

Question: Can a freshwater clam live with a goldfish?

Answer: Yes, as long as your aquarium has fantastic filtration.

© 2010 Isadora


Brooke on July 05, 2020:

What do fresh water clams eat

Not you problem on April 06, 2020:

Do you need to have fish

and the fish to make the tank dirty and the clams eat it?

Barber on April 17, 2019:

Can I use dirt as sand for my clam

Me on April 24, 2018:

Just got two clams one died you were really helpful

Shelby on January 15, 2018:

I have clams and they’ve got this like white stuff coming off of their shells there cleaning my tank pretty nicely the algae starting to dissipate and I do you feed them more algae with a dropper so I can like feed by squirting some in instead of just pouring a lot of algae In but what is the stuff comming off there shells I also have calcium rock soaking in the container I put the food in so I can have calcium for them too what’s going on with them

Chris R. on August 04, 2017:

One of my clams is fully open and ive had him only for a couple days. What does that mean?

Joshua on July 05, 2017:

How much copper in the water can kill a clam?

julia on June 02, 2017:

what happens when you find a lake water clam or mussle

shawna on December 08, 2016:

I have had a clam for about a year now...I put her where the water current flows at her and feed her algae wafers . I position it about 2 inches from her mouth and while the shrimp eat at it the water current carries pieces of it to her. ..she opens real wide when i do this, about every 3 days . also I don't allow my water to be "sparkley" clean, it isn't filthy but if a very small amount of particles are swirling around , it will also provide food for her.I have also learned that if I place a piece of moss over the back half of her shell and being placed where the water current flows at her, she doesn't move around ...which also tells me she is eating well and content in the tank.

Jo on November 27, 2016:

How long should it take for new clams to start filtering? I received an order of 15 small clams two days ago. They are divided into 3 tanks. They are all alive, but only about 4-5 have buried themselves. I have also not seen any visible change in clarity of the water. Does it take them a while to acclimate and get going?

Also - what do you find to be the best temperature?b I have read some things that suggest a cooler temperature is better. Thanks!

David Grover on October 31, 2016:

What is the best type of water for keeping clams? I have a 3ft by 1.5ft by 1ft tank with 3 large goodies and 6 white clouds with a decent filter and kept at 22 degrees Celsius.

chriss on May 21, 2016:

kinda looking around the web for info like, preferred ph, substrate type ( I keep aragonite in my tank and suspect that it may be a bit sharp for their lil foot) preferred temp , water hardness so on... any help would be appriciated

Marco on March 10, 2016:

Hey I just found two live clams in my Creek and iam trying to take care of them but I'm not sure if my tank is the best thing for them cause my tank has gravel instead of sand . is that okay ? And was wondering if my plecostamus may eat them ? And i was wondering if it is legal even to take these clams from the creek ? I would appreciate your response and wanna thank you for all the info I've learned on here!

toya on January 02, 2015:

Hey ! Its me again so you just buy the ingredients and mix it & drop it in the fish tank ?? So to lay them on substance side , that's the side with the 2 holes on it ??

toya harris on January 02, 2015:

Hello ! so your clams recipe is real meat ??

Vivian on October 24, 2012:

I added 2 clams about 2 weeks ago. My tank was cycling because I had just done a big water change and also added new fish. After adding them one dug himself in just at the surface and I think they were moving...very slightly, but yesterday morning saw one was on top of gravel wide open. I waited till this evening and took it out when I saw it was the same. Did I kill it?

Isadora (author) from Tennessee on June 18, 2012:

Yes, they can kill your clams. They are pretty nasty fish in the tank mate personality department.

I keep my tanks no less than three inches deep with substrate. You can move the clams without harming them, yes. They will just move around on their own though.

Megan on June 18, 2012:

Also, I have sand in my tank about 2 inches, but the bigger calm doesn't fit completely under the sand, only about half way. Is this a problem? Does he need more sand? And if so can I just pick him up and move him and add more sand and put him back

Megan on June 18, 2012:

I just bought 2 calms, the small one buried himself immediately and the large one about 48 hours after being put in the tank. The small one resurfaced a few days later. My 2in convict has been picking at him since, can he kill the calm? What are some good and bad tank mates for clams?

hi friend from India on April 18, 2012:

more informative

kiwwi on April 07, 2012:


Isadora (author) from Tennessee on April 07, 2012:

I have a natural aquarium so do not use carbon to filter it. You probably can use it though.

Provide enough fine substrate that they can fully bury themselves--this depends on the clams size. My substrate is anywhere from three to nearly six inches deep. Its sand and silt substrate.

No, they do not harm your plants. They will help to keep the substrate aerated/turned though! I love clams and miss mine dearly, lol. Hubby accidentally killed mine. Sigh.

kiwwi on April 05, 2012:

how much substrate do you need to keep calms and will they destroy plants? Also should I use a carbon filter with the clams?

Isadora (author) from Tennessee on March 20, 2012:

Here is a link to that food recipe.

Isadora (author) from Tennessee on March 20, 2012:

If their shells are tightly closed, they are probably okay. You can just keep checking them everyday, a couple of times a day to make sure they aren't dead. That or take them out. If you have a small air pump, you can keep them in a large bowl of tank water.

They need more than a few bits of leftover food to survive. I wrote a hub on food you can make for the clams. Good luck!

HeidiJoMar on March 20, 2012:

I have 3 freshwater clams. They are half white and they have brown on them as well. The brown is peeling off allthough. I have had them for about 5 days know and they have not moved at all. I was told that they are bottom feeders and the eat left over food. I have some nvery cool fish in my tank and i love them all. I am afraid they are dead. I ac not smell them due to bad cold. What do i do? I have expensive fish in my tank that i donot want to get sick. They include prehistoric goby, african butterfly fish, elephant nose, fire eel, black ghost knife fish, clown knifefish, 2 african clawed frogs and a few more. Very unsure what to do at this point. An suggestions?

Isadora (author) from Tennessee on March 12, 2012:

If it is still cloudy, you can do a partial water change. Make sure the water you replace it with is dechlorinated.

When you feed them, make sure you slowly aim the food towards their feeding tube. Use water the same temperature as the aquarium water.

I use a syringe without a needle to slowly drop food over their feeding tubes. Try mixing the crushed food with tank water and making a slushy with it. They really like tiny foods so if the crushed flakes are too big they wont eat them.

I have another hub on here on the recipe I used to feed my clams. Its pricey when buying the ingredients but they last a long time.

Here is the link to the food recipe.


leelee on March 12, 2012:

how will i know if they dead.. just cos it would be very smeely?.. and wat shall i do about the cloudyness.. will that clear on its own ?.. x

leelee on March 12, 2012:

just grinded up fish flake.. i read up and it said that was ok for them .. is that right ?

Isadora (author) from Tennessee on March 11, 2012:

The cloudiness may be a bacterial bloom. It usually means something is off with your parameters. I'm not sure what to tell you other than keep your eye on them and yank them out if they die.

What are you feeding the clams?

leelee on March 11, 2012:

i got them Friday and sunday now and they still the same .. they are closed and have been sat on the sand in same place since then.. ive read that the tank ment to get really smelly if they dead but dont smell any different from how its always been.. have noticed that water has gone slightly cloudy too.. unless that's from the cucumber that i give my plecs.. x

Isadora (author) from Tennessee on March 11, 2012:

They could be dead. Are they open or just laying on the surface closed?

Sometimes they will come to the top of the sand for a bit--they don't usually stay above the soil long, unless they are sick/dead.

Pick them up and give them a whiff. If they smell rotten, chunk them.

Make sure you only use dechlorinated water in their aquariums. My husband added tap water to my tank and it killed ALL of my clams within hours. I was so upset.

leelee on March 10, 2012:

i just got 2 clams .. there are both just sat on the sand .. ive had them about 2 days .. havnt noticed a change in them .. they are both just sat on 1 side of there shell.. are they ment to do anythin .. do they open ?

John on February 09, 2012:

Haha, thanks for the advice!

Isadora (author) from Tennessee on February 06, 2012:

I really don't know, lol. I probably wouldn't eat them because clams filter the water to get food. Lord only knows what chemicals they might have eaten. :O

You could probably make fish food outta them though.

I'd leave them alone. Just makes your pond more biologically complete! :-)) I love those little guys!!!

John on February 06, 2012:

Thanks for your reply!

Yes these are amall clams. And just out of curiosity, are these clams edible? I could make a meal of clam spaghetti out of them!

Isadora (author) from Tennessee on February 05, 2012:

Getting your pond to a good nitrate level shouldn't harm your clams. If they all died at once, it may harm your water chemistry. If a few died at the same time, you have enough water to probably handle it.

I am assuming these are small clams.

I've had things die in my ponds and the fish did fine. They just pretty much ate the dead things.

John on February 05, 2012:

My above post got cut off when I accidentally hit Post Comment.

I guess this is how the normal Eco system works. The question is, if I brought down the nitrate to more acceptable levels, 20-30ppm, would it affect the clams? I have detritus in the substrate which I guess the clams can still feed on. Any comments appreciated!

Thumbs up for this site!

John on February 05, 2012:

I have a small outdoor pond 260gal with koi. I have hard water and zero ammonnia and nitrites, however I have high nitrates in the region of 70ppm which I attribute to my plants dying due to predators like birds and even snails! My tank used to have a lot of algae due to the high nitrates and while doing a cleaning on my substrate, I found clams in there. Initially it was only 2, then it grew to about 10 or so (not sure how many are hiding further in the substrate). I do not mind having these clams in the pond, however hearing that they contribute to ammonia spikes upon death makes me a bit worried even when i have a relatively large body of water. I recently saw a snail opened up halfway and a few snails and some kind of worm feeding on it. I guess this is how a normal eco

Isadora (author) from Tennessee on January 24, 2012:

You're welcome. Thank you! :-)

TheUsedCarGuy from Melbourne Australia on January 24, 2012:

Great tips! Thanks :)

Isadora (author) from Tennessee on January 08, 2012:

Your questions got cut off.

This should work for the Mississippi mussels, yes. :-)

Some clams are real travelers and might escape their cups. All of mine stayed put, as long as they were fed regularly. Hungry or stressed clams tend to move around as they try and find a better place to live.

They should make neat additions to a nature tank! Good luck. :-)

bugguy123 on January 08, 2012:

I would like to keep a variety of Mississippi River mussels for display at a nature center.

Do they actually stay in a container with holes put in the substrate?

Would your feeding recipe work for them? Do the

Isadora (author) from Tennessee on December 17, 2011:

I'll be honest with you ...I wouldn't put anything else in your tank.

I'm almost positive the convicts would harass your clams to death though.

craig on December 17, 2011:

I have 6 convicts and 4 brisstlenoses 2 rainbow sharks a golden shark a green terror a ghost knife and a yabbie. Can I put a mussel in with them in a 3 and a half foot tank?

Isadora (author) from Tennessee on November 06, 2011:

Thank you! :-)

Steve Andrews from Tenerife on November 06, 2011:

Voted up for this very interesting hub!

Isadora (author) from Tennessee on October 28, 2011:

That much bioload may kill your clams. You would have to have a kick-butt filtration system set up. You can do natural filtration or mechanical. The turtles may eat the clams though.

potatochobit on October 06, 2011:

I have a baby turtle tank

and the turtles are soo messy!

they tear the food pellets when they eat and it gets everywhere

the water clouds up instantly

I am wondering if a clam can help this?

Isadora (author) from Tennessee on September 21, 2011:

I would check them daily or at least every two days. Check your ammonia levels once a week too. If you look closely at the substrate, you should see the clams mouth opening. As long as that is moving(filtering)the clams are alive.

If they die, clams can kill your fish if you have them in a small tank. The bigger the tank, the better. That way the ammonia spike isn't so harsh. Make sure you feed the clams because they will starve to death if you do not.

Steve on September 21, 2011:

I just added two clams to my tank and it's not something I've ever looked up really and the pet shop couldn't tell me much either but I like things that are different.

One dug himself into the gravel within hours but the others still sitting on the top. How risky is it keeping them with how you said about the ammonia spike when they die? I've got a fair few fish and don't want to risk any.

Isadora (author) from Tennessee on September 15, 2011:

I would say it buried itself in the substrate FishLover. Look really closely at the substrate--you can usually see their little tubes sticking up, filtering the water. It would be like two small, pulsating holes in the sand.

Isadora (author) from Tennessee on September 15, 2011:

They might eat them, Chris, lol. Turtles are devious little devils! Of course, it would be a yummy snack for them, lol.

chris on September 15, 2011:

Can I put a couple clams into the tank with my 2 red-eared slider turtles?

fishlover on September 13, 2011:

Wow... I recently went fishing with a friend and i caught a perch a bluegill and 2 clams. I still have my perch and hes happy in his makeshift tank until i make a native one for him, the bluegill died before getting home and the 1 clam was already dead and when i put it in my fish tank it was eaten by my dojo loach i assume. But the other i put in i left on top of some sandy gravel and the next morning i use my net and find him burried and now i cant find him anymore (i assume he dug a tunnel) but anyway its my first time with clams and im at least happy.

Isadora (author) from Tennessee on August 20, 2011:

Well, if they are a cold water clam, then they should be okay. Might carry a parasite or disease though. I believe goldfish like hard water, so they would work with the clams preference in water hardness.

kitt on August 20, 2011:

thanks for the info, I just got a bunch of clams the size of my finger, I'm not sure how big they grow I got them on a river, I wonder if they are safe to put with a goldfish?


kaitlyn on July 22, 2011:

i have pet clams-i'm growing them as big as i can but so far they are about he size of my thumb

Aquaticopia on February 25, 2011:

Errg, sorry I've never used hubpages - that video was youtube > search "Asian Clam", unless this link works:

Aquaticopia on February 25, 2011:

Great info! I had always wondered if clams removed any waste *chemicals* in addition to their filter feeding.

@Darlene, when introducing the clam to the aquarium lay it on the substrate and when it feels safe (is not disturbed for a little bit) it opens up and uses a "foot" (looks like a white or pink tongue) to upright itself and feel its way into the substrate. It then wedges its way down into the substrate. As long as your substrate is deep enough, it will position itself vertically (where the two shell parts join is facing 'up & down'). You should be able to see two little syphoning holes showing up through the substrate. If your clam is laying horizontally and under the substrate - it may be dead? I linked a video of my clam when it first dug into the sand to illustrate it.

darlene on December 08, 2010:

Thank you for all this good information. At the Pet store they show the clams position up straight and mine is not its laying like a clam, is that normal? My clam is also buried. Could someone give me suggestions about the daily living habit of a clam ??

Isadora (author) from Tennessee on July 29, 2010:

Heya Sterling,

Thank you for your kind words!

I love keeping just about any kind of animal. Clams have always fascinated me--I can remember keeping them as a child. Lots of fun!

The only diving I ever did was the kind where you hold your breath and hope you don't land on a gator!

Sterling Carter from Indian Mound, Tennessee on July 29, 2010:

Wow, what an interesting Hub. I am a black water diver by trade of nearly 20 years. I have spent much of my life underwater searching for and learning about bivalves.

Here in Tennessee we have a few clams but mostly we have mussels. These are harvested for their mother of pearl. They are heavy, thick and can grow quit large.

I used to keep at least one of each species that I could legally harvest in an aquarium along with other wild caught fish.

I had to quite that when one of my larger shells, a 5 lb Washboard managed to get his foot between the silicon and the glass and broke my 200 gallon tank.

Lesson learned.

I greatly enjoyed this Hub


Isadora (author) from Tennessee on July 29, 2010:

Hello Shad,

I advise against putting wild-caught animals into your aquarium. They carry diseases that probably aren't in your tank, this is bad for your Jack Dempsey.

If the clam dies it can wreak havoc on your system. If you do decide to keep it, I advise giving it its own container and remember to feed it!

If it were me, because of its injury, I would humanely put the clam to sleep.

I hope this helps and feel free to ask more questions. :)

shad on July 29, 2010:

i found a clam in a pond and put it in my fish tank with my jack dempsey. its about 4 to 5 in and it has a crack in its shell, is it safe to keep it in my tank and will it breed by its self thanks to who ever can answer my ?

Isadora (author) from Tennessee on April 15, 2010:


*Yes, you can acclimate the clams just like fish.

*Algae powders can be purchased at various stores online, Ebay, or even at your local pet shop. I really enjoy using organic Spirulina, the clams eat it up quickly too.

*Mine do eat small particles of fish food but it may be difficult to get enough food for them crushed into small enough particles. They really do eat a lot and constantly! :-O

Here is the link to my clam food recipe.

Brad on April 12, 2010:

I was wondering, how do you add clams to an aquarium and how can you feed them? Do you add them like fish you add fish? To feed them when algae is not present, can I just crush up fish flakes?

Isadora (author) from Tennessee on February 25, 2010:

You're very welcome James. :-)

James on February 25, 2010:

Thank you for pointing out that clams act as animals not plants. They do not remove nitrites/ammonia; they remove suspended particles. Clams grow best in unfiltered, cloudy water.