Commonly misspelled on the forum as "cuddle bone" or "cuddlebone.
For many aquarium keepers, it is vital to add calcium for snails or up the PH in their tank. An easy way to do this is by adding a chunk of cuttlebone. But what IS a cuttlebone? Read on!
1: Where does a cuttlebone come from?
Cuttlebones come from a creature called a "cuttlefish", highly intelligent and social relatives of octopuses and squid. The "bone" is a modified internal shell that serves as a support and also buoyancy control (think of it as a swim bladder made of porous bone).
2. What is a cuttlebone used for?
The cuttlebone is comprised of delicate calcified microscopic plates that are easily carved, crushed and powdered when dry. Historically they have been ground into powder for polishing mediums, used by artisans for sculpting, and even as casting molds for molten metal. In your aquarium, cuttlebones are added directly to the water to help raise PH and as an excellent source of bio-available calcium for snails to nibble on. More commonly, cuttlebones are marketed towards bird owners as both calcium supplements and 'beak conditioners," as they are an excellent medium for birds to polish and sharpen their beaks, and provides chewing entertainement.
3.Where do I get a cuttlebone?
Most pet stores that sell bird supplies will have cuttlebones on hand. Typically packaged on a hanging card in the bird department, they usually look a little something like this:
You can also buy them online, which can be cheaper. Be sure to purchase cuttlebones that are not colored, flavored, or scented. They are sometimes packaged with a metal clip or holder, which should not be used in your aquarium. They come in many sizes, get whatever type suits your needs. I purchased my last batch in a 12-pack from Amazon.
4. How do I use the cuttlebone in my aquarium?
The dried cuttlebone is filled with air. Some aquarists simply place the cuttlebone in the aquarium and wait for it to become waterlogged on its own. I broke mine in half, placed it in a coffee cup, and poured boiling water on it, holding it down with a spoon. After a bit I poured off the cooling water and applied a second bout of boiling water, which chased out the rest of the trapped air. It also left me satisfied that it was clean and germ-free. The cuttlebone sank readily after that, and simply buried it partially in the substrate of my tank, in a corner where it would not possibly catch on my fish's fins. When my snails want a calcium snack, they nibble on the cuttlebone.
If the cuttlebone looks "dirty" or grows algae/diatoms, don't worry about it, it'll just be more tasty for the snails! Eventually the cuttlebone will break down or be used up by either the snails or the water... in which case simply add another piece. Easy-peasy.
The More You Know!
Cuttlefish - Wikipedia
Common cuttlefish, Sandy Seafloor, Octopuses & Kin, Sepia officinalis at the Monterey Bay Aquarium
Cuttlebone - Wikipedia