What Is The Best Substrate For Your Aquarium?

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The substrate used in your aquarium is an important but often overlooked component in the creation of a healthy aquatic environment. It is the foundation upon which your aquascape will be created. There are numerous substrate options available that will allow the aquarist to create an appealing simulation of the natural environment of the fish and plant species in their tank. Brightly colored substrates that would never occur in a natural setting are also available and are usually not a good choice when setting up your aquarium.

Caution needs to be taken when deciding on the substrate you will use. Depending on the type of fish in your aquarium some substrates will perform much better than others and will actually contribute to the health of your fish. The same can be said of a planted aquarium. Choosing the right substrate can make a huge difference in your ability to maintain the health of your aquatic plants. The wrong choice will hinder the ability of the plants to flourish and leave you disappointed with the results. Though you may be tempted to buy the least expensive product available this will probably not be the best choice. Spending a little more at the outset will enable your aquarium and its inhabitants to thrive and add to your enjoyment as an aquarist.

In this article we will identify the best substrate to be used in a variety of settings. We will look at how different substrates work better with certain fish species and which is best to use in a planted aquarium. Hopefully this will guide you in making your decision when purchasing the substrate for your aquarium. In particular we will look at substrates recommended for use with goldfish, bettas, African cichlids and planted freshwater community aquariums.

What Is The Best Substrate For Goldfish?

The very popular goldfish is kept by many aquarists around the world. Often purchased as juveniles they can be small fish just a few inches in size. Goldfish can grow to be quite large and require a large tank in which to thrive. They are also commonly kept in outdoor fish ponds.

When visiting your local fish store you may see small goldfish in a tank with a substrate consisting of marbles or brightly colored gravel. While this may make for appealing viewing it is not conducive to keeping your goldfish healthy and happy. Goldfish have very specific behavioral characteristics that preclude the use of many types of substrate available. Goldfish love to forage along the bottom your tank, picking through the substrate for morsels of food. This behavior should influence your decision when choosing their substrate.

Gravel of any size is not a recommended substrate for a goldfish tank. This is for a number of reasons. One of the most popular substrates available is variously colored, small, pea-sized gravel. This type of gravel is totally inappropriate for a goldfish tank. As your fish grow and go about their natural foraging behavior they will pick up pieces of this gravel in their mouths. On occasion they will swallow these pieces of gravel and this can cause serious health effects such as a ruptured digestive tract. This can lead to the death of your fish, so small gravel should be avoided when planning a goldfish tank.

Another problem shared by all size gravel is that there is space between the individual pieces in which food debris can be trapped. As it dissolves it creates toxins that are harmful to your fish. Goldfish spend a lot of time at the bottom of your tank making them especially vulnerable to these toxins. Marbles share this problem of spaces for food to become trapped and are also not a good substrate for goldfish.

Water softness can be a problem as hard water is beneficial to the goldfish’s fins and scales. Crushed coral is often used to increase water hardness but should not be used for goldfish. The sharp edges of the coral pieces are dangerous to the foraging fish and can cause mouth injuries.

Sand is by far the best choice in substrate for your goldfish aquarium. It packs tightly together eliminating the problem of spaces for food particles to be trapped. Debris will settle on the surface of the substrate and be easily removed. Additionally and just as importantly, sand will not hurt the goldfish if it is ingested. It may even be beneficial if eaten as it passes through the fish and helps clear out its digestive system. Choose sand for your goldfish substrate.

What Is The Best Substrate For African Cichlids?

Aquarists who choose to keep African cichlids should be aware that their care is demanding and specific water conditions are required for their survival. African cichlids originate in the Rift Lakes of Central Africa. These lakes have a naturally high PH and this needs to be recreated in your cichlid tank.

Another characteristic of cichlids is that they are avid diggers and love to burrow and create caves. This behavior will uproot plants and the fish will then consume them, so plants are usually not used to decorate a cichlid tank. Rocks and caves are vitally important to your cichlid tank. Cichlids are naturally aggressive and territorial. They will claim a cave and attempt to drive all others away. To minimize the aggression your tank mates will exhibit you need to have a sufficient number of caves for the cichlid population you plan on keeping.

With those factors in mind we see that a proper substrate for a cichlid aquarium will need to help buffer the water’s PH. It will also need to allow for digging without injuring the fish and enable you to create substantial rock and cave formations that will not be moved or toppled by digging fish.

Though some aquarists choose to go with a bare bottom tank free of substrate for their cichlids this is not the best layout for your cichlid tank as it eliminates the opportunity for the fish to dig and tunnel. Small and large gravel are inappropriate for reasons similar to that of goldfish. Smaller gravel can be ingested and cause health issues and all size gravel can cause toxins to be created that are dangerous to your fish. Cichlids like the bottom of the tank and will be susceptible to these toxins.

Plain, well washed sand is an excellent choice of substrate for your child tank. It will work well with the cichlids foraging habits and serves as a stable base for your rock and cave work. There are substrate products available that also help in buffering the PH and will keep it at the high range required by your fish. Coral sand or sand containing aragonite are recommended as they are excellent at performing this buffering. CaribSea’s Eco-Complete for cichlids is a good choice for your substrate, but any coral or aragonite sand should work fine. Crushed coral if around finely enough will also buffer the water and let your fish forage safely.

What Is The Best Substrate For A Freshwater Planted Aquarium? 

Choosing the right substrate for your freshwater planted tank requires you to put some thought into what type of fish and plants you will be keeping. Using gravel can pose the same problem of accumulating toxins and cause health issues with your fish. You can minimize these problems with vigorous gravel cleaning combined with regular water changes but there are other considerations. If you plan to keep any of the popular Cory catfish then you need to find a substrate that is not sharp as that can injure the delicate undersides and barbels of these fish. Some the more popular substrates designed for a planted aquarium are rather rough and will not serve well in a tank with Cory cats.

In some cases your best solution is to use two kinds of substrate. The bottom layer will be intended to promote plant growth and can be rough. Covering this with a thinner layer of a rounded gravel will protect your bottom dwelling fish while affording the benefits of the plant enhancing substances in the bottom layer of substrate. We will talk about the bottom layer designed to assist in plant growth.

Regularly, well washed sand will work in your planted tank but may pack too tightly to allow the root systems of certain aquatic plants to flourish. Mixing sand and some fine gravel can help with this issue. There are substrates specially designed for planted aquariums that will alleviate this problem. They are produced with a clay or lava base and are excellent at both biological filtration and promoting root growth. Two excellent products that are very similar are Flourite manufactured by SeaChem and CaribSea’s Eco-Complete for the planted aquarium.

Both of these substrates contain essential nutrients to promote plant growth. Flourite is made of a very porous clay gravel and is an excellent substrate for your plants. It does not soften the water or change PH levels. It will never need to be replaced for as long as your tank is operational. It is available in a regular sand variety as well as black, dark and red options. You can use this in a freshwater tank with or without plants.

Eco-Complete has similar properties. It is made from volcanic soil and contains many of the same nutrients and minerals as does Flourite. In addition it contains live bacteria that rapidly converts fish waste into plant food. This product is available as a very fine black substrate or a slightly larger red version. Either of these two products would be an excellent choice for the substrate in your planted aquarium.

What Is The Best Substrate For A Betta Tank?

Betta fish are kept in a large variety of different size tanks. Some aquarists will use very small tanks that will only house a single fish and some artificial decorations. In other cases a medium sized planted aquarium may be where you choose have your betta live. A betta needs a resting place in the tank so even in a small tank it is advised that you have at least one artificial plant for its use. Live plants are even better if that is an option you wish to pursue. You also want to choose natural colored gravel or sand for your betta tank. Though bright colors may appeal to the aquarist they can be the cause of undue stress in your specimens. The gravel’s colors will also compete with the fish’s natural coloration.

In a small tank that will only contain a betta it is critical not to use gravel that allows food particles to get trapped and disintegrate. With no bottom feeders to help clean up, any food going to the bottom will be subject to decay. Though bettas may lounge about the bottom your tank they are not bottom feeders and will not perform this duty in their tank. For this reason, large grained gravel or marbles are not to be used in a betta tank.

With these thoughts in mind we can see that in many cases the same substrate choices that work well for planted freshwater tanks will work well for your betta. If you are decorating with artificial plants then you do not need to go to the expense of a Flourite type of substrate, but sand would be an excellent choice. A betta tank with live plants will achieve the same benefits as those mentioned above for a freshwater planted aquarium.

What Is The Best Substrate For You Aquarium?

As you can see from the above discussion, this is a question that cannot be answered without asking other questions. Fish and plant selections are crucial to determining the substrate that will work best for you. A general rule for all tanks is that large grained gravel is problematic as bed for toxin production.

I hope this discussion has helped you in choosing a substrate for your aquarium. Take the time to plan your aquarium before purchasing the substrate and you will have a much easier time of maintaining a healthy and visually appealing tank.

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