How many pounds of substrate do I need for a 10 gallon tank?

When setting up a new aquarium, one of the most important decisions is choosing the right substrate. The substrate forms the foundation of the tank and can impact the water parameters, plants, and overall aesthetics. For a 10 gallon freshwater planted tank, you will need between 10-15 pounds of substrate depending on the type you select.

Substrate Types

There are several options when it comes to freshwater aquarium substrates. Here are some of the most popular choices:

  • Gravel – Inexpensive and readily available, gravel comes in a variety of sizes and colors. Standard aquarium gravel ranges from 2mm to 5mm in diameter. You would need approximately 10 pounds for a 10 gallon tank.
  • Sand – Very fine grained, sand allows plants to root easily. Pool filter sand or play sand are common choices. Expect to use 10-12 pounds in a 10 gallon aquarium.
  • Soil – Specially formulated aquatic soils release nutrients to help plants thrive. They come in fine grains similar to sand. You may need as little as 8-9 pounds for a 10 gallon tank.
  • Fluorite – A porous clay material, Fluorite does not need to be replaced over time. It is heavier than other substrates, so 8-10 pounds should be sufficient for a 10 gallon planted tank.
  • Aquasoil – Designed for planted tanks, aquasoils are enhanced with nutrients and buffers that keep pH stable. Despite being lightweight, they have high nutrient content. Use 10-12 pounds for a 10 gallon aquarium.

Substrate Amount Guidelines

As a general guideline, most planted tank owners recommend using 1-1.5 pounds of substrate per gallon of water in the aquarium. This allows adequate root penetration for most plant species. For non-planted tanks, you can use less – around 0.5-1 pound per gallon.

Based on these guidelines, here are the recommended amounts for a 10 gallon tank:

  • Heavily Planted Tank – 10-15 pounds
  • Moderately Planted Tank – 8-12 pounds
  • Sparsely Planted Tank – 5-10 pounds
  • Non-Planted Tank – 5-10 pounds

Sand, gravel, soil, and Fluorite weigh about 100 pounds per cubic foot. That means 1 pound will fill about 0.75 liters of tank space. Aquasoils and some specialty substrates are much lighter at around 50 pounds per cubic foot. 1 pound equates to approximately 1.5 liters of volume.

Additional Factors

While the general guidelines provide a starting point, there are a few other factors to consider when choosing substrate for a 10 gallon tank:

Fish or Shrimp

The type of livestock may dictate substrate choice. Sand may not be ideal for bottom dwelling fish like Cory catfish. Small shrimp and snails can get trapped in deep gravel. Bare bottom tanks are sometimes used for certain species.

Aquascaping Approach

Dutch style aquascapes with densely planted stems may require deeper substrate beds. Sand blasting grit can be used to create sloped terrain. Small sized gravel highlights the scale for nano tanks.

Water Parameters

Substrates like Fluorite and aquasoils buffer water to maintain ideal pH and hardness. This can be beneficial for species that prefer soft, acidic conditions. Inert gravel has no impact on water chemistry.


While specialty substrates can enhance plant growth and aesthetics, they also come at a higher price. Basic gravel and sands offer an inexpensive alternative.

Mixing Substrates

Another option is mixing substrates to combine benefits. A common approach is using aquasoil or Fluorite on the bottom to provide nutrients to plant roots, then capping it with sand or fine gravel to give a clean appearance. The cap layer also prevents the lighter substrate from getting stirred up by fish.

Total Amount Needed

Based on the 1-1.5 pound per gallon guideline, most 10 gallon planted tanks will use 10-15 pounds of substrate total. Here is a breakdown:

  • 10 pounds – Lightly planted tank with a sand cap over soil/Fluorite
  • 12 pounds – Moderately planted tank with plain gravel or sand
  • 15 pounds – Heavily planted Dutch style tank with aquasoil

For non-planted setups, you can get away with less – around 5-10 pounds total. This allows for some sloping from front to back without compromising too much water volume.

Substrate Depth

In addition to the overall weight amount, the depth of the substrate layer is also an important consideration. Recommended depths are:

  • Planted tanks – 2-3 inches front to back
  • Non-planted tanks – 1-2 inches

Deeper substrates allow better root penetration for plants. Shallower depths help prevent anaerobic pockets in non-planted tanks. The slope from front to back can vary based on the aquascape design.

For a 10 gallon tank, 2-3 inches equates to roughly 2-4 pounds per square foot of surface area. So another way to estimate substrate needs is to calculate the surface area footprint and multiply by the desired depth.

Substrate Calculator

To make things easy, you can use an online substrate calculator to determine how much you need based on the tank dimensions, desired depth, and type of substrate. Here is an example for a standard 10 gallon tank:

Tank Dimensions 20 x 10 x 12 inches
Substrate Choice Fluorite
Front Depth 2 inches
Back Depth 3 inches
Total Substrate Needed 14 pounds

Simply plug in the numbers for your particular tank setup and substrate preference to get an accurate estimate.

Buying Extra

When purchasing substrate, it is advisable to buy a little extra than the estimated amount needed. Having some leftover allows you to add more if the initial amount is not deep enough or to rescape and supplement areas down the road.

For a 10 gallon aquarium, buying an extra 2-5 pounds is reasonable depending on planted or non-planted setup. It is better to have too much than not enough when starting a new tank.

Rinsing the Substrate

Most types of new aquarium substrate will require some rinsing prior to use. This helps remove dust and debris that can cloud your tank water.

Place small amounts of substrate in a strainer or colander and run under tap water until the rinse water runs clear. Shake off excess moisture before adding to the tank. Repeat with all the substrate you plan to use.

Heavier substrates like gravel and sand may only need one quick rinse. Very fine and lightweight substrates will require more rinsing to get clean.

Adding Substrate

Once fully rinsed, you can begin adding the substrate to the empty tank. Pour or sprinkle it in gradually while tilting the tank to spread it evenly across the bottom.

Use a ruler or aquascaping tool to gauge depth and contour the slopes. Position hardscape materials like rocks or wood as needed. Compact the substrate gently with your hands or a spoon.

Go slowly to avoid clouding the water too much. You can finish by vacuuming up any fine particles that settle after the substrate is fully in place.


There are a few safety precautions to keep in mind when using aquarium substrate:

  • Wear a dust mask when rinsing dusty substrates
  • Use heavy gloves when handling sharp substrates like crushed coral
  • Rinse outdoor to prevent plumbing clogs from substrate dust
  • Go slowly to avoid scratching the tank with tools
  • Don’t stir up substrate once the tank is filled


Over time, organic debris and waste will accumulate in the substrate. To prevent toxin buildup, you should:

  • Use a gravel vacuum to clean substrate weekly at water changes
  • Stir the upper layer with a tool to prevent compaction
  • Trim plant roots that start to take over the substrate
  • Replace inexpensive substrates every 2-3 years
  • Supplement root tabs for plants in nutrient deficient substrate


Choosing and adding the right freshwater aquarium substrate in the proper amount is a key foundation to a healthy planted tank. For a standard 10 gallon aquarium, you will need approximately 10-15 pounds depending on whether it is heavily planted or not. Select a substrate suitable for the types of plants and livestock. Mixing products can combine benefits. Test the estimated amount in an online calculator and buy a bit extra when purchasing substrate. Rinse thoroughly before adding to the tank gradually. Follow the guidelines provided here and you will be off to a great start!

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