How to Add Calcium to Freshwater Aquarium?

Aquariums are a great addition to your home. Not only do they add personality to your room, but they also liven up the place.

If you want pets but don’t spend too much time at home, fishes are a great option since they don’t need much one-on-one time like other animals.

Aquariums are a great option for people who are revamping their homes, but what is important to keep in mind is maintenance.

Aquariums need regular maintenance – it is essential to clean your fish tank and change the water regularly; otherwise, your aquarium will start smelling.

This smell will keep on increasing and may spread in your room or affect the fish negatively if you don’t clean your tank.

While cleaning your aquarium, always make sure to add calcium to the water.

Read more to learn why your aquarium water needs calcium and how you can add it.

How to Add Calcium to Aquarium Water

It is necessary for your fish tank to always maintain a healthy ecosystem for all the inhabitants of the water.

Various factors affect the health, growth, and lifespan of your plants and fish.

Whether it’s the oxygen level, the temperature, the water level, or the nutrients level – it is your job to ensure that it is all in place so none of the organisms die.

If your aquarium has different types of fish, you need to keep in mind that they all might have different requirements.

For example, a fish more sensitive to cold water might not survive in the winters very long without a heater as compared to a fish that can survive cold water.

Calcium is a vital nutrient for fish because it helps with growth. Besides helping the animals grow, calcium can help with healthy eggs and the healing of all kinds of shells.

Calcium levels vary in saltwater tanks and freshwater tanks.

It is a little harder to keep a constant calcium level in freshwater because of the composition.

Since saltwater is already rich in salts and minerals, it is always a good idea to add calcium to your freshwater aquarium.

If your water does not have hardness, this means that the calcium will not stay for long.

This is when you need to add more calcium to it. You can add calcium to your freshwater tank through the following ways:


This is one of the easiest ways to increase the calcium percentage in your freshwater aquarium.

Carib Sea ACS00110 Crushed Coral for Aquarium, 10-Pound

It requires no extra work; simply add corals to the bottom of your aquarium.

Ground corals contain minerals like calcium and they are a great plant to decorate your aquarium with.

You can do this whenever you’re cleaning the tank or changing the water. Make sure to add it to your list, so you don’t forget to do it every time.

Liquid Additives

Another way to add calcium to your freshwater aquarium is through liquid additives.

You can get liquid additives from your nearest fish store at affordable prices.

Be careful when adding these – you don’t want to add too much and change the concentration of the water.

Make sure to pour it in a jar before adding it to the water, so you know exactly how much you have to add.


Cuttlebones are quite literally made of calcium carbonate, so it is always a good idea to add a few to your freshwater fish tank.

These shells will provide calcium to your organisms and also make your aquarium look better.

Egg Shells

Eggshells contain a lot of calcium, so it is a great idea to add eggshells to your aquarium if you don’t have any other options.

Be careful – eggshells can easily make a mess, so place them where the fish are not able to reach.

Take them out after a while and dispose of them.

Don’t forget to remove them from your aquarium or they might cause a mess inside your aquarium, which may result in a bad smell.

Before adding calcium to your aquarium, make sure you are aware of the calcium concentration the inhabitants of your water can take.

If the calcium concentration is too much, scaling might occur, which means you will have to start cleaning your filters quite often.

Calcium for Snails

If your fish tank has snails, you should always add calcium to your aquarium.

Unlike fish, snails can survive in all kinds of temperatures.

If your aquarium has tap water, you don’t need to do anything because the snails will get their calcium from that.

On the other hand, if your aquarium has freshwater, you should feed your snail calcium-enriched foods.

You can get these items from your local grocery store or a nearby pet shop.

They are affordable and easily available, so even if you don’t have much time to buy specific food for your snails, you can simply get calcium-enriched foods whenever you go to get grocery supplies.

A good example of calcium-enriched foods is fresh spinach.

Spinach has a very high calcium content, but you have to be very careful – don’t just throw a spinach leaf in the water.

It will simply float at the top and cause a mess. Instead, take the spinach leaf and put it in a small bowl.

Add water to the bowl and then microwave both of the things. After you’re done, let it cool for at least 60 seconds, and then put the leaf on the substrate of your tank.

Your snail can easily reach the substrate, so wait for it to do just that.

There is a very small possibility that it will finish the whole thing, so just check the substrate after a few hours.

Take out whatever the snail hasn’t eaten; if you leave the spinach in the tank, it will cause a mess in your aquarium and even affect the quality of your substrate.

Related Article: How to Get Rid Of Snails in an Aquarium?

How to Maintain an Optimal Aquarium Environment for Your Organisms

When it comes to maintaining an aquarium, it is not always easy to keep in mind all the factors that help you keep a clean tank for your fish and plants.

On the one hand, your aquarium needs beneficial bacteria, which keeps your fish healthy, but on the other hand, it is easy to kill beneficial bacteria when you’re trying to get rid of all the harmful bacteria.

If you want your aquarium to have the optimal temperature and the best light, here are a few things you need to do regularly:

Clean the Aquarium

When cleaning the aquarium, make sure to remove the fish first.

You can fill a bucket with existing aquarium water and keep your fish in there (to make sure they remain in a familiar environment).

Don’t forget to remove the filter, the substrate, the heater, and all the decorations before starting the cleaning process.

Remember that your filter has beneficial bacteria as well. So, remove any gunk in the filter, but don’t rinse and try to clean it completely. That will do more harm than good.

You don’t have to change the water every time you clean the aquarium.

Water can be changed every couple of months, but make sure it doesn’t take longer than that because it can result in your plants and fish dying.

Clean the Water & Maintain the Temperature

To make sure the water stays clean and at the right temperature, a good idea is to check the water temperature every day.

It is essential to check the water temperature on days it gets too cold or too hot.

You can check the temperature by placing a thermometer inside the water. This way, you’ll know if your fish need the heater or not.

When it’s too cold, you can simply open some windows and keep the tank in front of the sun.

A few other ways to make sure your water stays clean and has enough calcium content include testing the water pH, ammonia, hardness, and nutrient levels.

You don’t have to do this every day, but it is a good idea to do it at least once a week.

This way, if your aquarium water has low calcium levels, you can simply make adjustments to make sure your fish have all the required nutrients they need.

Clean away all the algae that may be forming at the bottom of the edges of your fish tank. Too much algae can cause oxygen depletion in your aquarium.

If your aquarium is made of acrylic, be very careful when doing this because you can easily cause scratches.

Clean the Gravel and Filter

A good idea to keep your aquarium clean is by vacuuming the aquarium gravel every once in a while.

This way, you can remove some of the waste and food that might not have been consumed by your fish.

Make sure to check the filter and replace the cartridge if necessary (again, only when necessary).

If your aquarium has a lot of decorations like lava rocks or even plastic plants, take them out while cleaning the aquarium (no need to rinse as these would also have beneficial bacteria).

Just clean it enough to get rid of any waste on it.

Focus on the Plants

While taking care of the fish is essential, the plants are just as important. If you believe that your plants might be rotting, make sure to cut the stem or remove them completely so they don’t cause further damage.

If your aquarium has freshwater instead of saltwater, it is a good idea to add calcium to it so your plants and animals can have the nutrients they need to grow and thrive.

To add calcium to your water, refer to all the ways mentioned above!

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