Gigas clam once lived in Waikiki Aquarium

Is Gigas Clam right for your aquarium?

Would you keep rhino in your bedroom?

No, never, don’t even think about it!

Gigas clam once lived in Waikiki Aquarium
RIP Gigas clam of Waikiki Aquarium

The largest member of the mollusk family: Tridacna Gigas, the giant clam that gave clams a bad, killer reputation is in fact the most gentle giant ever.

I won’t go too much into detail about the care instruction because frankly, anyone who isn’t a public aquarium with thousands of gallons of tank space is simply irresponsible in considering housing this animal in their puny bucket.

You may not need a lot of light for Gigas clam as it is one of the more light tolerant clams. But you will need to have at least a 3’ x 2’ footprint of space and 2’ vertical space for the clam’s potential size. You must also consider that this clam is a heart beating animal with gills actively sucking oxygen out of the water. This means you need an enormous amount of water volume and turn over to generate enough dissolved oxygen in the tank. If you try to house one in a 500 gallon tank with 50 fish you will wake up to a tank crash from suffocating animals.

Additionally, these animals can live 80+ years in the wild. And they never stop growing for as long as they live. So the the time they have reached 2’ in length you will be dumping a gallon of calcium and alkalinity a week just to keep up with the consumption, not to mention other trace elements.

Oh have I mentioned clam spawning yet? Adult clams spew millions of gamets during spawn ritual and if not caught and dealt with this is a serious contamination to the aquarium. To put in perspective, the 3’ Gigas clam spawned in the Waikiki Aquarium while they still had them. The result was a complete water change for the 20,000 gallon system. Yes! That’s not a typo, four zeros, twenty thousand gallon of seawater. It will cost an average hobbyist $10,000 just on salt for the water change.

Anyways, now that we have a good understanding that housing a Gigas clam is no ordinary joe’s task, this clam is right for you if you can answer yes to these questions:

  1. You have a system with at least three zeros in its total water volume.
  2. you are relatively young and plan to live and care for this clam, who can possibly outlive you, and that you have a plan for the animal if you kick the bucket before it does.
  3. you have a good automated system to monitor and supplement trace elements to maintain water stability. Particularly to catch up against the fast depletion of calcium and alkalinity.
  4. You have a reservoir of equal water volume as your display tank to perform emergency water changes should the clam’s breeding practice or demise compromises your water. You must react quick as a giant’s death can spell doom for the small ecosystem you’ve created.