One of the easiest substrates to use for your aquarium is gravel. I love using gravel in my aquarium because it can provide great color, doesn’t need to be replaced, and is super simple to clean. A question I get asked a ton is whether aquatic plants will grow well in gravel.
Gravel is perfectly suitable for some aquarium plants. However, most gravels are inert substrates and do not provide nutrients; so the plants used must be able to get their nutrients from the water column. Plants that need nutrition from the substrate can be placed in aquatic pots.
Using gravel in your tank can affect plant growth, depending on what vegetation you use, so keep reading to learn more.
How to Grow Aquarium Plants in Gravel
What substrate is used in an aquarium is incredibly important for your aquarium’s health and looks? A good substrate will both keep your aquatic plants alive and help your aquarium look amazing. After all, we build aquariums for them to look good, do we not?
Though, I think I’m getting a bit ahead of myself.
After all, what even is a substrate?
A substrate is a material used for the floor of the aquarium to plant whatever aquatic plants you want and to improve the aesthetics of your aquarium. Substrates commonly used are:
- Sand, both fine and coarse
- Substrate soils
Some substrates will affect the pH balance of the water, these are known as active substrates.
Substrates that do not affect the pH balance of the water are inert substrates.
Most gravels are inert substrates and do not provide nutrition to plants, whereas substrate soils are active substrates and do provide nutrition. Plants that need nutrition from the substrate will not work well being planted in gravel.
When using gravel as a substrate for plants, it is ideal to have the gravel pebbles be three to eight millimeters thick, with the optimal size being around five millimeters. Gravel thinner than three millimeters can damage the fragile roots. Gravel any thicker than 8 millimeters can block proper root growth and development.
Using gravel in an aquarium is surprisingly easy. The gravel layer should be no more than 4 inches thick. Plants can be placed within the gravel, gently covering any bulbs or roots with the gravel.
What are the Best Plants to Use With Gravel?
Due to gravel not providing nutrition to the plants planted in it, the best plants to use with gravel are plants that thrive off of getting the required nutrients from the water column around them.
These plants won’t necessarily be luscious and luxurious with colorful fronds and ferns, but they will look nice, especially when taken care of.
Luckily, the kinds of plants that work great with gravel are also quite easy to maintain. For this exact reason, gravel is popular among people with busy lives but who also want a beautiful aquarium.
Some of the best plants to use with sole gravel are:
- Amazon Sword
- Java Fern
- Elodea, or Pond Weed
- Water Hyssop
- Java Moss
- Marimo Moss Balls
All of these different plants look great and are super easy to care for. My favorite among these is the Marimo Moss Balls.
Marimo Moss Balls are such a unique plant and are so easy to maintain. The moss balls are actually a species of algae that produces all of its own food through photosynthesis. Don’t worry, they’re safe for your fish and tank.
Not only are moss balls easy for beginners, but they look so cool! The Marimo Moss Ball is also symbolic of good luck and everlasting love. Because of this, they can make great gifts to loved ones that share your love for aquariums.
What to Do If Your Aquatic Plants Won’t Grow in Gravel
Unfortunately, not all aquatic plants can grow in only gravel.
Many plants require more nutrition than can be acquired from the water column itself. Gravel does not provide any nutrition to plants, so these plants do not thrive when using just gravel.
However, if you are still wanting to have more demanding plants and use gravel as your substrate, there are a couple of solutions to this problem!
Mix Substrate Soil With Your Gravel
Perhaps the more difficult of the two solutions presented here is to mix substrate soil with your gravel.
By mixing the soil with your gravel, you allow the plants to get the nutrition they need from the soil while maintaining the aesthetic that gravel provides.
However, there are a couple of difficulties with this method.
Firstly, substrate soil affects the pH balance of the water, so you will likely need to use a pH buffer to maintain the environment that your fish and plants require.
Secondly, substrate soil needs to be changed out every once in a while. Having the soil mixed in with the gravel can make it slightly difficult to clean out and change. Gravel does need to be cleaned occasionally anyway, so changing the soil can be done at the same time.
Use Aquatic Pots to Plant in Gravel
A slightly easier method of using hungry plants in gravel is to plant them in aquatic pots. Using pots to contain the soil where it’s needed will allow for your plants to have all the nourishment they need without all the hassle of cleaning dirt from gravel can be.
Planting your plants in these pots is also super easy! Simply fill the pots with the soil you wish to use, plant the plant in the pot, and place it where you want in your tank, covering the sides with gravel.
Because substrate soil is involved, you will more than likely have to use a pH buffer. Double-check with your soil and your environment requirements before using a pH buffer.
When you need to replace the dirt, simply take the pot out and replace the dirt! Simple as that.
Using this planting method also frees you to use whatever kinds of gravel you want. No longer will you have to worry about if the gravel is too coarse or too fine because the plants are safely contained in their planters.
Gravel can be a wonderful substrate to use in aquariums. Always remember to keep the gravel within five millimeters in thickness and to combine it with substrate soil if you like to have higher maintenance plants.