If you have some freshwater snails in your home tank, you surely know the importance of having a constant source of calcium. Since snails’ shells are made mostly from calcium, lacking this vital substance can be detrimental to their health.

In today’s article, let’s have a look at where and how you can get calcium for snails in fish tank.

Why Do You Need Calcium For Snails In Fish Tank

When it comes to calcium for snails and shrimp, the consensus is that these invertebrates rely on calcium for a living. Up to 90% of their bodies are from calcium carbonate, which ensures the strength and structural integrity of their shells.

Given how soft and vulnerable their inner organs are, being protected by the hard shells is the top priority for freshwater snails.

Furthermore, since aquarists tend to put snails in a community tank, the risks coming from their tank mates are significantly increased. Were a snail and an aggressive fish to collide with each other, it would be much better if the snail can guard itself against sharp bites.

Sources Of Calcium For Mystery Snails

Now that you have understood the role of calcium in snails’ well-being, let’s talk about its main sources. Usually, calcium can be found both in the surrounding environment of these animals and the food they are offered.

Water conditions

Most bodies of water are filled with minerals, including calcium. However, if the water is treated incorrectly, your snails may experience a decrease in calcium supply.

Hence, water mineralization is necessary should you want to keep the level of calcium steady. That is not to mention how mineralization can be helpful for pH balance maintenance.

Daily meals

Calcium can easily be absorbed through food. Anything from cuttlebone or veggie is substantial in its calcium content, giving your snails a quick boost in their shells.

Both cuttlebone and veggie are cheap and highly accessible, so feel free to pick what suits your needs the best. Our recommendations would include leaf lettuce, basil, zucchini, cabbage, and soybean.

How To Increase Calcium In Aquarium

Increasing the level of calcium in aquariums is quite effortless, providing that you follow the guidelines below.

Mineralize the tank’s water

Mineralization refers to the process which increases a certain environment’s concentration of minerals. In this particular case, you will need to double down on how much calcium your tank has.

The most basic approach here is to boil and crush eggshells. Eggshells are almost identical to snails’ shells, making them suitable for increasing the calcium content. Moreover, they are dirt cheap and do not take much time to prepare.

All you have to do is to soften the shells, then proceed to crush them into fine powder. Spray the powder so that it sinks to the bottom and leave it there.

Another option is to use cuttlebones. Similar to eggshells, cuttlebone is rich in calcium. They come from cuttlefish and do not serve any other purpose rather than decoration. Feel free to leave these cuttlebones inside your tank. Gradually, they will dissolve and turn to calcium. However, you will need to remove the cuttlebones after a few months. Once decaying for too long, cuttlebones can smell horrible, which can be uncomfortable for your home.

If you happen to have some spare oyster shells, using them to increase the calcium supply is also recommended. Not only do they contain calcium, but they are also rich in salt. Adding one or two shells to your home tank makes for a more attractive sight and a constant source of minerals.

In case you need a quick boost in your tank’s calcium concentration, using calcium blocks would suffice. As the name indicates, calcium blocks are 100% calcium pressed into holdable pellets.

Once exposed to water, it will dissolve slowly within two weeks. While they do not have any aesthetic purpose, calcium blocks work much faster and are more efficient when it comes to increasing the calcium supply.

Improve food’s calcium content

As explained above, feeding your snails with calcium-rich food is the quickest way for them to absorb this substance. There is only one thing to be aware of here, which is to blanch the veggie beforehand.

This way, all of the food will stay fresh and edible for at least 2 days.

Add ground corals

Why use a boring substrate when you can have a whole coral colony at home? With stony exoskeletons, corals make for great decoration and calcium supply.

You can also use ground corals to prevent your fish from charging at the bottom since reflective glass can confuse them.


1. How often do I need to feed my snails with calcium?

Snails cannot store calcium for later use. Hence, you will have to feed them with calcium daily. Pay attention to both their food and their surrounding environment, as these two factors can directly affect the calcium consumption of your snails.

2. Can snail have calcium powder?

Yes. While it can be slightly more expensive, calcium powder makes for great calcium intake. Snails can take in calcium powder either directly or via food. You can also spray the powder into the water and let it mineralize the tank. Do not forget to dilute the powder beforehand, as its original concentration can be too much for your snails.


Now that you know everything about calcium for snails in fish tank, do not forget to apply this knowledge to real life. Check the tank’s calcium level constantly and provide timely solutions should it go down.

In case you think our advice has been helpful, please spread the word and see what your fellow aquarists have to say!

Alex is a pet freelance writer and editor with more than 10 years of experience. He attended Colorado State University, where he earned a Bachelor’s degree in Biology, which was where he first got some experience in animal nutrition. After graduating from University, Alex began sharing his knowledge as a freelance writer specializing in pets.

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