How to Add Calcium to Aquarium for Snails

Calcium is one of the most important nutrients for all kinds of animals. The good news is that snails are one of the easiest pets to keep with a good diet and aquarium. However, many owners find themselves short on calcium as snails do not consume enough food to meet their needs.

In this article, we are going to discuss the most effective ways to add calcium to your aquarium not just for your snails but also for your fish.

Why Do Aquariums Need Calcium?

Calcium is, obviously, an essential element for all living organisms. It’s often used as a measure to determine the health and growth phases of different animal species. As part of our fish’s diet or water intake system in aquariums, we need calcium along with other nutrients such as phosphorous and nitrogen balance but if there are not enough protein-rich foods to meet the needs of your snails this can happen suddenly quickly leading to the quick death of snails.

What Causes Calcium Deficiency in Aquarium?

As previously mentioned in this article, stress plays a huge role in creating that lack of resources and waste products with which your aquariums can become lusher so aside from neglecting them to necessary foods, aquarists should also learn how to deal with stress properly as well.

How Much Calcium Should I Add?

Calcium levels should be at about 70-90 mg/L calcium to ensure adequate amounts of calcium potential; however, if you are averse to adding any supplements, you may want to set your rate lower than that. Snails do not need high concentrations of calcium in their diet and do very well with the level of 70-90 mg/L as long as the aquarium is not overcrowded and has enough space for snails and other fish.

There is no hard and fast answer here though most aquarists seem to agree that one teaspoon per 5 Gallons (18 liters) will do the trick, again, you should aim for levels closer to 70 -90 mg/L. If you are using an external calcium source such as Coral-Plus or Majestic Marin, then just add the appropriate amount of that to your aquarium water and forget about it (although be sure to check the directions on those products for specific dosage instructions).

How to Add Calcium to Aquarium Water

Adding calcium to aquarium water is simple and can be done in several ways. The most popular way seems to be by using an internal “buffering” agent such as Coral-Plus or Majestic Marin but there are other, less common methods too (more on this below).

In any event, adding calcium should not take long and you can do it quickly before feeding time without disrupting your tank’s equilibrium. If possible, verify the calcium levels of your aquarium water using a quality test kit before you begin to add calcium so that you know what level to aim for.

Frequent Water Changes

One of the most important things you can do to keep your aquarium healthy and happy is to make sure that you’re regularly water changing it. Not only will this help to remove excess debris and unwanted organisms, but it will also distribute the calcium evenly throughout the tank so that all fish are getting an equal amount. While there’s no realistic way to completely replace lost minerals with water changes alone, doing a partial cleanse every 1-2 weeks will go a long way in keeping your tank functioning and healthy.


Corals make a great addition to most tanks as they’ll bring life into the tank itself due to their bluish color clustered together aside from being the best sources of calcium for your snails. However, one often has difficulty coping with these species when attempting to do so on your own primarily because of one issue. First off is the fact that if not handled correctly many polyps will break and tear which in turn can lead to water infection. If that happens it’s recommended you get rid of them altogether by simply removing the damaged corals from your tank, not losing any though at least one more set too so this way all pieces are transferred properly, giving us a clean new piece.

Liquid Additives

Another popular way to add calcium to your aquarium is by using liquid additives such as Coral-Plus or Majestic Marin. These are typically easy to administer and require minimal disruption of the tank’s chemistry so long as you’re able to screw on the dropper cap with an airtight seal (and make sure it doesn’t freeze over winter!). Just be sure not to use too much at one time; if you do, adding more gradually may be a better idea to avoid issues like water stagnation or the flimsiness of your coral colonies. Note that liquid additives are only recommended for new setups as they can often be harmful to established tanks and coral polyps.

You may also check out some rules on which water additives are best by either taking into consideration one particular person’s opinion against another or just what aquarists have decided to use so you must consider this when searching around. Another form of these water additives is a liquid or powder added directly to the actual soil where live rocks and aquarium gravels are placed on. This can be helpful as well if using natural materials, since some other forms like bacteria cultures and activated carbon may end up losing their power after a while with the environment thus needing a replacement for good results in your setup.


A popular way to add calcium and other nutrients to your tank is by using cuttlebone. Cuttlebones are very easy to obtain, as they can either be bought pre-frozen or fresh out of the ocean. They come in a variety of shapes and sizes so it’s best to measure out how much you’ll need before adding it directly into your tank substrate. Once added, cuttlebones will slowly break down and release their nutrients over time.

Egg Shells

Another popular way to add calcium and other trace minerals is by using eggshells. These can be easily obtained from local farmers markets or even online stores like Amazon, and unlike cuttlebones, they won’t release their nutrients until you either break them down or soak them in water for a few hours (depending on the size). Once added, eggshells will help to absorb excess nitrates and phosphates from the water column as well as provide a physical barrier against bacterial growth.

Calcium Blocks

If you’re looking for a more permanent solution to adding extra calcium to your aquarium, then calcium blocks could be the answer. Unlike other additives that need to be added regularly, these blocks are meant to sit in your tank and provide the necessary nutrients without any additional effort on your part. Simply add them before water changes or when you notice that there’s been an increase in algae or nitrates levels, and they’ll do their job of helping to increase the calcium levels in your tank without costing you a penny.

Crushed Oyster Shells

Finally, if you can’t or don’t want to go the extra steps of adding calcium blocks or snails to your tank, then crushed oyster shells could provide a comparable solution. Simply add them directly to your aquarium and they’ll work their magic by providing extra nutrients and minerals while also cleansing the water. While this option won’t be as easy or convenient as some of the others, it may be all that you need to keep your tank healthy and functioning properly.

Liquid Calcium Chloride

Liquid calcium chloride is a more convenient way to add extra calcium to your aquarium. Simply add it directly to your tank and it’ll help increase the level of nutrients while also helping to cleanse the water. While this option may be cheaper than some of the other additives, it may not be as effective or long-lasting.

Flowering Plants

Adding flowering plants to your tank can provide several benefits, including adding more calcium and other nutrients to the water. Not only that, but they often act as a natural filter by removing debris and pollutants from the water. While this option may be more expensive than some of the others, it could be worth it if you’re looking for additional bonus features in your tank.

Additional Snails

One of the most important additives for any aquarium is calcium, and if you want to add it to your tank without adding additional bulk or weight, then snails are a great option. Not only do they possess a high level of natural calcium levels themselves, but they’re also quick and easy to keep as pets so you can be sure that there will be enough shells available when you need them. Simply put snails into the tank with some fresh water and they’ll start to filter feed, which will result in them excreting calcium-rich shells.

Wonder Shells

Wonder Shells are a natural, organic additive that helps to increase the level of calcium in your aquarium. Simply add them directly to your water and they’ll do their job of increasing the mineral levels while also helping to cleanse the tank. While this option is more expensive than some of the others, it could be just what you need to keep your fish healthy and happy.

Small freshwater snail, known sometimes as a faucet snail, sometimes found in aquaria.

When Should I Add Calcium to Aquarium?

Adding calcium should be done as close to feeding time as possible without disrupting the tank’s balance; however, it is not necessary every day and some aquarists prefer to wait until there are noticeable signs of illness or deficiency before adding supplemental calcium. It is also important to note that calcium levels can rise and fall quite a bit over a day so it’s best to check them every few hours during daylight hours.

What Happens If I Add Too Much Calcium in Aquarium?

If you accidentally add too much calcium then there is a danger of adding too much magnesium which can cause serious problems with fish behavior and even death. If you suspect that you have added too much calcium, then the best thing to do is to remove some of it by pouring it out and adding fresh water until the aquarium’s calcium levels are back where they should be.