How Much Crushed Coral Per Gallon of Freshwater: Let’s Find Out! 


Coral is one of the most important ecosystems in our oceans, and it can be crushed into a powder to create an effective treatment for rosacea. Find out how much coral you need to make your own face mask that helps with inflammation!

Crushed coral is a popular aquarium decoration. It is made from the skeletons of hard corals that have been crushed to create a porous material. The crushed coral can be used in freshwater tanks as well as saltwater tanks. This experiment will help determine how much crushed coral per gallon of fresh water it takes to raise ph by one point.

Crushed coral is an excellent technique to lower the pH of your aquarium. To cope with the pH, crushed coral generates a buffer solution. Crushed coral in excess, on the other hand, might be harmful to your tank. 

So, how much broken coral do you need per gallon of freshwater? 

Crushed coral may be Substrate is a term that refers to a substance that is used to make something else. or added to your filter. Using 20 grams per gallon for substrate is an excellent idea. You must add filters depending on your requirements. There are several more considerations to be made while using crushed coral.

This is simply a brief overview of the crushed coral industry. We’ll go through how to add crushed coral to your freshwater aquarium in greater detail in this post. Let’s get started!

Can Crushed Coral Be Used in a Freshwater Tank?

Is crushed coral healthy for freshwater, you may wonder? 

Yes! Crushed coral is beneficial to freshwater aquariums for a variety of reasons. Crushed coral, when Substrate is a term that refers to a substance that is used to make something else., helps to keep the pH of your freshwater stable for a long period. As a result, you won’t have to worry about your tank being too acidic. 

What Is the Purpose of Crushed Coral in an Aquarium? 

Crushed coral, as previously said, helps to raise and maintain the pH of your aquarium. Understanding the process, on the other hand, is crucial.

Calcium is the primary component of crushed corals. Carbonic acid is formed when calcium combines with water, acting as a buffer solution. The buffer solution responds to neutralize the acid if the pH drops. 

Crushed coral helps control the pH of your freshwater tank in this manner. You should, however, keep an eye on the pH level. Here are several test kits you may use to do so. 

Crushed corals now only disintegrate in low pH environments. So, if there’s too much broken coral, would that be a problem?

Yes, crushed coral, like everything else in your fish tank, is a necessary evil. If your tank’s substrate has too much broken coral. Because of its size, it will obstruct the flow of water. 

Food leftovers, animal carcasses, and plants may also get lodged, generating a foul odor. If you’re using it on your filter, too much of it might have a negative impact on your pH. As a result, the quantity of crushed coral in your tank must be carefully monitored.

Do You Need a Lot of Crushed Coral?

When it comes to the all-important subject of crushed coral, how much should you use? Many individuals have trouble determining how much crushed coral they need. For these phases, the crushed coral is added in a different way.

The quantity of crushed coral required for each step, as well as the technicalities involved, are detailed below. 

Substrate is a term that refers to a substance that is used to make something else.

The tank’s substrate is usually a crucial component. Your substrate impacts the quality of your tank since it is the foundation. In addition, too much or too little substrate might be a major problem. 

It’s best if your substrate is at least 2 inches thick. Otherwise, the water flow in your tank may be disrupted. As a result, you must bear this in mind while laying down substrate.

12 cup substrate per gallon is a decent rule of thumb. Crushed coral weighs around half a pound per gallon. Calculate the quantity depending on the size of your tank, then adjust your substrate. 

Based on the size of the tank, you may calculate how much crushed coral you’ll need. Let’s say you’ve got a 55-gallon tank. So, how much crushed coral do you need for a 55-gallon aquarium?

You may use roughly 30 cups of crushed coral in a 55 gallon tank. This is around 30 pounds of crushed coral. However, you must first position the substrate before moving on to the next step.

Even using crushed coral as a substrate, you may need to adjust your pH in certain circumstances. The crushed coral must then be added to your filter as a rapid boost.

If you’re wondering how much crushed coral you’ll need for your tank, here’s a rough estimate. The most common sizes of aqueon tanks are shown in the table below.

You may use this table to help you figure out how much you need.

Applied to Filters

Crushed coral is an excellent approach to cope with your tank’s rising pH. It’s a little more difficult, but it’s a terrific technique to keep your tank constant. 

In most cases, crushed coral may be added to your filter. When your pH is out of equilibrium, it will disintegrate. As a result, it’s a progressive procedure that might take a few weeks. 

As a result, 12 cup per 20 liters of water is recommended. Fill your filter halfway with crushed coral and set it in your tank. To see whether the pH has changed, check it every few days. 

If you don’t obtain the desired change after a week, add 14 cup per 20 gallons. Continue until you get the desired result. It’s time-consuming, but it’s well worth the effort.

To ensure that the crushed coral dissolves properly, you’ll need a high-quality filter. If you’re searching for a nice filter for your aquarium, here are some of our suggestions.

These are some of the finest freshwater aquarium filters we could discover. 

Check out the chart below to figure out how much crushed coral you’ll need: 

TimePer gallon, how much do you need?
Initial 12 cup of vinegar per 20 gallons of water 
Once a week until the appropriate pH is reacheda quarter cup per twenty liters of water 

When you achieve the proper pH level, however, cease adding crushed corals right away. If you still have some coral in your filter, get rid of it.

Manually used

You may also manually employ crushed coral in your aquarium. This procedure, however, is only used in an emergency. 

Simply take a handful of crushed coral for a quick pH increase. After that, put it in your aquarium. However, make sure it isn’t more than 14 cup. Because you don’t want to meddle with the water’s pH level. The coral will blend in with the rest of the aquarium and begin to work.

However, be sure you don’t go overboard. Not only will your pH rise dramatically, but it will also make your tank unclean and mushy.

Crushed Corals Have an Impact on the Following Factors 

We now understand the importance of crushed corals in our freshwater aquarium. We must also be aware of the details. A fish tank is a complicated process in which everything you put into it is dependent on others. 

Everything in your planted tank, from the lighting to the water flow, is dependent on each other for stability. Knowing how your crushed coral reacts to everything else in your tank is crucial. 

Before you add crushed coral to your aquarium, there are a few things to consider:

Hardness of Carbonate

Hardness of Carbonate or KH is the amount of carbonates and bicarbonates dissolved in the water of your tank. This refers to the amount of acid it can neutralize before the pH of your tank is changed.

Keep in mind, however, that broken coral has no effect on the pH of your aquarium. It raises the amount of Calcium Carbonates in your tank, which lowers the kH. The kH is then used to adjust the pH of your tank.

When it comes to deciding the quantity of crushed coral to use in your pond, understanding the kH level is critical. To respond to your query, how much crushed coral is required to increase kH?

It’s crucial to remember that the greater the KH, the less likely your pH will fluctuate. As a result, aim for a KH of as high as feasible. If your KH falls below 4.5, you should begin adding crushed coral in proportion to the size of your tank.

Plants that grow in water 

Plants are a necessary component of every aquarium. They substantially alter the appearance of your tank’s design. They are also necessary for your plant’s stability. They aid in the provision of oxygen, the improvement of filtration, and the promotion of algae development.

As a result, learning how to care for plants is crucial, yet it’s something we frequently overlook. If the pH of your tank rises dramatically, it might have a negative impact on the plants. It’s important to remember this while using crushed corals. 

Adding too many crushed corals at once might cause the pH to fluctuate dramatically. Making it difficult for your plants to survive. As a result, bear it in mind!

Generally, Plants that grow in water require a pH of 6.5 to 7.5. However, if you want a higher pH, make sure your plants will survive that. 


Fish, like plants, need a lot of care when it comes to the pH of their aquarium. So, if you’re going to raise the pH of your pond, make sure your fish are prepared for the change. 

Crushed corals are also very good to some fish. They are used to high pH levels in general. They also benefit from the habitat that crushed corals generate. 

Crushed corals are beneficial to a variety of fish species, including shrimp, Ebi, and cichlids. If you have these fish in your tank, crushed corals are a preferable choice for the substrate. 

Many fish, on the other hand, have a hard time with high pH. Also, if the grains of your coral are too large, smaller fishes may get caught in the substrate. So, before you put crushed coral in your tank, bear these things in mind.

Crushed coral is a no-no if you have burrowing fish, snails, or turtles in your aquarium. Crushed coral grains make it difficult for them to move around on the bottom. As a result, there is a danger of injury and property damage. 

Detritus is present. 

For your tank, this is a double-edged sword. Coral grains, on the one hand, are rather large. As a consequence, they often trap dead plants and fish. They don’t float about because they catch the trash. As a result, you’ll have a fresh and tidy aquarium.

However, when the dirt builds up on the substrate, it becomes mushy. Cleaning has become a nightmare as a consequence. This is time-consuming and labor-intensive.

So, how do you clean broken coral that has been used?

Cleaning broken coral is really rather easy, despite how time-consuming it is. Using a vacuum, remove as much trash as possible from the coral. After that, just rinse it clean and you’re ready to go!

Crushed coral is worthwhile if you’re willing to put in the work. However, if vacuuming and cleaning seem like too much work, you will not enjoy the experience. 

How to Include Crushed Corals in Your Aquarium 

Let’s talk about how to add crushed coral in your water now that we’ve covered everything. Crushed coal may be used as both a substrate and a filter. The steps are as follows:

Substrate with Crushed Coral: 

Make sure your tank is empty if you’re going to utilize crushed coral as a substrate. After that, take the crushed coral and put it in the tank’s very bottom. There are no gaps or uneven sections since everything was spread evenly.

Also, you can add gravel, rocks, etc. with the coral to give your entire tank a better look. Once the substrate is placed, plant your Plants that grow in water and finally fill up your tank. Plants that grow in water like dwarf hairgrass might die if the substrate isn’t made properly.

Adding Crushed Coral to an Existing Aquarium

It’s extremely easy to add crushed to an already established tank coral if you have a tank that needs a pH increase. 

Crushed coral is most often added via the filter. Measure your coral carefully before rinsing it. This will clean the crushed corals of any dust and grime, preparing them for the filter. 

You may also just place the coral on top of your aquarium and let it to disintegrate. While it is faster, it might cause your pond to become sloppy and filthy.

After that, just insert them in the appropriate section of your filter and you’re ready to go!

How to Use Crushed Coral 

If this is your first time working with crushed coral, there are a few things to bear in mind. Otherwise, you risk doing more damage than good to your tank. The following are some suggestions:

Wait patiently.

The most frequent mistake made by most individuals who attempt crushed coral is adding too much. Crushed coral takes a while to set and modify the pH of your water. However, for a speedy transformation, individuals often put too much at once.

This causes the pH to change drastically and damage the flora and fauna of the tank. So, always Wait patiently. with your crushed coral. It can take a few weeks for your coral to get set, so keep that in mind. 

Replace them as soon as possible.

Crushed corals persist for a long time, but they aren’t indestructible. It’s because your crushed corals are decomposing that your pH is dropping. However, once they begin to disintegrate, they don’t take long to do so. 

So, if you see that your pH is dropping, take action right away. It’s possible that not adding additional corals or altering them will have a significant impact on your pH.

We’ve now covered all there is to know about crushed corals. We’ve even shown how to utilize them in your aquarium! 


Is it necessary to replace my crushed corals on a regular basis? 

Although there is no definitive solution, it usually lasts six months with no problems. If your pH drops suddenly, though, make an adjustment right away! 

Is it possible to blend other materials with crushed coral as a substrate? 

Absolutely. You may combine similar-textured items with the corals, such as gravel. Mixing sand or other similar materials, on the other hand, will just make the tank hazy and difficult to manage. 

Is broken coral safe to use in a canister filter? 

Yes! Crushed coral may be used in a canister filter. Filling more than 25% of the filter with coral, on the other hand, will result in a lot of trash and residue. 

Final Thoughts

Finding the greatest materials for your freshwater tank will always be a priority if you’re an aquarium enthusiast. In an aquarium, crushed coral is one of the most prevalent and beneficial materials. 

The number of crushed corals, on the other hand, has always been a problem. As a result, we attempted to answer the all-important issue of how much crushed coral should be used per gallon of freshwater. 

We hope we’ve been of assistance!

Crushed coral is a natural sedimentary rock that is composed mainly of calcium carbonate. The wonder shell is a type of clam that has been crushed and used as a decorative item in the ocean. Reference: crushed coral vs wonder shell.

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