How Much Gravel For 10 Gallon Tank And Other Substrate Options You Can Use

Estimated read time 8 min read

For many beginners, it’s difficult to know how much gravel for a 10-gallon tank is enough.

In this article, we will show you some options and give you some easy calculations to help you figure out how much gravel you need for your 10-gallon tank.

Setting up a beautiful and functional fish tank is a lot of work. You have to choose the right fish, right size and shape of the tank, plan the décor, decide on the plants you want to grow in it, and of course, add the gravel.

Gravel is a type of substrate, which is the bottom layer. In this case, the bottom layer of the fish tank where necessary bacteria can live is basically a combination of many tiny rocks, of varying sizes.

Gravel is an important part of a fish tank and is necessary for a clean aquatic environment for the fish. It ensures the presence of necessary bacteria and supports the nitrogen cycle that breaks down fish waste and food. This keeps the water unpolluted for a relatively long time.

So how much gravel for a 10-gallon tank is really needed?

Considering you have a normal rectangular tank, the answer would be 10 to 15 pounds of gravel (1 – 1.5 pounds per gallon).

For common dimensions of 20”x10”x12” (LxWxH), 10-pound gravel will make a 1-inch deep layer in the base of the tank, if you spread it evenly.

But like most things in life, it’s more complicated than that.

Equipment You Might Need For Your 10 Gallon Tank

  1. Aqueon 10 Gallon Fish Tank Kit
  2. Fluval M Aquarium Heater
  3. Python Pro-Clean Gravel Vacuum
  4. Marina Algae Magnet Cleaner
  5. API Freshwater Master Test Kit

Why Use Gravel in Your Tank?

Before spreading pounds of gravel in the base of the tank, you must be curious why is it necessary in the first place? Here is why:

  • It houses necessary bacteria. Crucial for clean and healthy conditions for fish in the tank.
  • Fish feel comfortable with gravel (or another substrate) because it imitates their natural habitat. A bare transparent bottom of the tank can be confusing for the fish.
  • Helps keep waste down rather than floating around in the tank.
  • Many fish and aquatic species like to burrow in the gravel.
  • Necessary for anchoring aquatic plants.
  • Adds to the décor.

It is also imperative that you choose the right type of gravel. If the fish are delicate, you cannot use gravel with sharp edges and big rocks. Otherwise, the fish will hurt their fins and mouths.

If the fish like to burrow in, choose gravel with very small rocks, so that fish can move in easily.

It is also necessary to keep the gravel clean, ideally using a gravel vacuum. It ensures that no food particles or waste gets trapped in gravel and rots.

Other Substrate Options

You can look into other substrates as well. But make sure you understand what’s best for your fish, and for the plants you want to grow in the tank.


Carib Sea ACS05820 Super Natural Moonlight Sand for Aquarium, 5-Pound
  • natural white creates great color contrasts
  • ph neutral ; used in salt and freshwater aquariums
  • no dyes or paints used
  • made in the USA

Sand is also used as a substrate. Many consider it visibly more aesthetic than the gravel since it blends in naturally. It also has an advantage if you have burrowing fish, or fish that like to sift through the water bed to look for food. It is easier for them to do that in the sand than in gravel.

Sand is so closely packed that nothing goes in it. That means waste sits on top, making it easier to clean. Some fish even eat sand to help with the digestion.

Sand has some disadvantages as well. Unlike gravel, its small particles can easily get trapped in the filter and clog it. Also, unlike sand, gravel allows water to pass through, preventing the buildup of too much amoeba or mold.

Deep sand can also form air pockets, trapping food and waste, turning them toxic over time. Once these pockets burst, the toxins are released in the water, making the fish sick. It’s also difficult to add sand as a substrate in the fish tank, especially when you compare it to gravel.

Aqua soil

Fluval Plant and Shrimp Stratum, 4.4-Pound
  • Mineral rich volcanic soil
  • Stimulates strong plant growth
  • Promotes neutral to mildly acidic pH
  • Suitable for plants or shrimp
  • 4.4 Pound bag

First thing you need to know about Aqua Soil is that its primary purpose is aquatic plant growth. It’s made by baking regular soil.

If your focus is more on setting up a planted tank than fish, aqua soil is your best option. It sustains and promotes a better plant growth than either sand or gravel can. It also has more nutrients to help plants grow and flourish.

Aqua Soil is also difficult to put in and replace. In the initial days, water needs to be replaced daily to clear out excess ammonia. Once it sets, aquatic plants are planted. Fish and shrimp can only be introduced after 3-4 weeks of planting.

It is advised to only use aqua soil if you are planning to grow exotic plants in your tank: plants that won’t take in sand or gravel. Otherwise, stick to other substrates.

Crushed Coral or Coral Sand

In some rare cases, crushed coral or coral sand is also used as a substrate. In most cases, it resembles gravel but with fewer options in colors and types. It’s also alkaline in nature which might be required for some fish species.

Since only certain types of African fish and very few plants can survive in this environment, your options would be fairly limited if you use this substrate.

Other than that, marbles, a combination of dirt and gravel, and pebbles are also used as substrates. But most people prefer gravel in their fish tanks.

So How Much Gravel Is Really Needed for a 10 Gallon Tank?

Unfortunately, there is no rule of thumb for this. Instead, there are a few generalizations. For a regular 10 gallon rectangular tank, 10 to 15 pounds gravel is enough. Spread evenly, gravel will be around 1 to 1.5 inches high at the base of the tank.

This provides a general setting for a fish tank, where you can go for some aquatic plants as well. Most fish are happy with gravel. It will add to the décor and will provide better aesthetics if you contrast it well.

But the same amount of gravel will not be suitable for a circular or cylindrical 10-gallon tank where the gravel layer will get higher. This will also become harder to clean since the waste and food will move deeper with the water.

On another hand, a thicker 2-4 inch layer of gravel might be exactly what you need for some kind of aquatic plants and digging fish. For that high a layer in your rectangular tank, you will need about 25-40 pound of gravel.

Simply put, in most normal cases, a 10-gallon tank will need about 10 to 15 pounds of gravel. In special cases, this amount can be increased or decreased

Keeping fish and preparing a fish tank is a very exciting part of the hobby. It requires as much care, consideration, and planning as it takes enthusiasm. But if you do everything properly, you will get to see exotic aquatic life thrive within your tank.

More Info About 10-Gallon Tanks

  1. Guide to Setting up Your 10-Gallon Planted Tank
  2. 12 Hungry Algae Eaters For Small Tanks 10 Gallons & Under
  3. Stocking A 10 Gallon Tank
  4. Best Small Catfish for a 10-Gallon Tank Setup
  5. Bottom Feeder Fish for a 10-Gallon Tank
  6. How Much Gravel For A 10 Gallon Tank
  7. How Many Neon Tetras In A 10 Gallon Tank
  8. How Many Guppies in a 10-Gallon Tank
  9. How Many Goldfish in a 10-Gallon Tank
  10. Easy 10-gallon Cichlid Tank Ideas
  11. Best Powerhead for a 10 Gallon Tank
  12. What Is The Best Canister Filter For A 10 Gallon Fish Tank?
  13. Gravel Vacuum For 10 Gallon Tank & Smaller
  14. Best Stands For 10 Gallon Fish Tanks

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