Whether aquarium plants need soil or not depends on the type of aquatic plant. Some aquatic plants absorb nutrients through their leaves and do not need a substrate for their survival. However, other aquatic plants like the ground cover plants and plants that grow from bulbs need soil to survive.
Let us explore the soil needs of different types of plants in closer detail to gain a better understanding of this subject.
The Basics Of Keeping Aquarium Plants
By understanding the basic needs of aquarium plants, you can maximize their lifespan and help them thrive in your tank setting.
The most important needs of aquarium plants are:
- Clean water,
- Nutrients for survival and growth,
- Proper substrate (for rooted plants).
Most aquarium plants thrive in water with pH levels between 6.5 and 7.8 at temperatures between 74°F and 80°F.
You should regularly change the water to keep it clean and hygienic. Replenish it at least bi-weekly.
In some places, tap water contains harsh chemicals that are unsuitable for aquatic plants.
If you live in such a place, use filtered water in your aquarium.
Different aquatic plants have different light needs. Most plants need 10 to 12 hours of sunlight for optimal growth.
The glass covers should be clean to maximize the penetration of sunlight into the water.
Some plants need intense light to survive. When growing such varieties, you may have to use an indirect light source.
Aquarium plants need various nutrients like nitrogen, phosphorus, iron, potassium, and manganese.
They absorb nutrients through their leaves, roots, or both these organs.
Aquatic plants obtain some of these minerals from fish waste in the aquarium.
However, you may also have to supplement it with liquid nutrients to ensure a regular supply.
Aquarium plants that grow in soil usually have specific substrate requirements.
Depending on the type of plant, you may have to choose fine, medium, or coarse gravel or sand.
The right substrate will ensure that the plant roots develop properly and anchor well in the substrate.
It will help them absorb all the nutrients that they need for their survival.
Do You Need (Or Don’t Need) Soil For Aquarium Plants?
Not all aquarium plants need soil for survival. It usually depends on how the plant absorbs its nutrients.
Some plants absorb nutrients through their leaves, while others use their roots.
Some plants can absorb nutrients through both their leaves and roots.
Plants that take in nutrients through roots are called root-feeders.
They need a substrate to survive. You must anchor them in the aquarium soil to let them grow and thrive.
The following types of aquatic plants fall into this category:
- Ground Cover Plants: These are true aquarium plants that belong to the very bottom of the tank. They quickly spread along the aquarium floor and even send out runners that develop into new plants. Vallisneria falls into this category.
- Node Propagators: Node propagators have long branches that break off when they grow too long. These branches will spring new plants when they are anchored in the soil.
- Bulbs: Bulbous aquatic plants will sprout only when planted in soil. They propagate by growing new bulbs.
How Much Aquarium Soil Do You Need?
The amount of aquarium soil you need for your tank depends on two factors:
- Size of the tank, and
- Desired depth of the substrate.
The depth will vary according to the type of tank.
For instance, the recommended substrate depth for a freshwater tank is 2 to 5 cm, whereas it is 5 to 7.5 cm for a planted tank.
To calculate the quantity of soil, you will need to find out your aquarium size in centimeters.
Then consider the depth you wish to keep for your substrate.
Now, calculate the required amount of soil by the following formula:
Amount of aquarium soil (in Liters) = length x width x depth / 1000
When adding substrate to the tank, it is a common practice to arrange it in a sloping fashion.
Professional aquascape experts usually prefer soil to gravel or sand.
It is because the soil is packed with nutrients and is a better medium for plant growth.
Sand and gravel do not contribute to the nutritional needs of aquatic plants. Hence, they are only suitable for decorative purposes.
Although soil is recommended for aquariums, you cannot just use garden soil for the purpose.
Always choose aquarium soil that is specifically developed for aquatic habitats to ensure the safety and health of your aquatic plants and pets.
Aquarium Plants That Do Not Need Soil
Aquatic plants that are not root-feeders derive their nutrients through the leaves. Hence, they do not need soil for survival.
Such plants are easier to grow and keep alive. They will float around the aquarium and make it lively and interesting.
Since these plants are relatively low maintenance, they are the right choice for aquarium owners who cannot invest much time into plant care.
Here are the 5 best aquarium plants that do not need soil.
1. Java Moss
Under the right conditions, Java Moss grows like a weed.
It is a hardy plant that hardly needs any care or maintenance. The plant adds a lot of greenery to aquariums.
Additionally, it also offers good cover for tiny fish, shrimp, and other small inhabitants.
Since it grows fast, you may have to trim it occasionally to keep it under control.
2. Java Fern
The Java Fern is a beautiful plant with lush ribbon-like leaves. You can tie it to a rock or wood in your tank, and it will slowly settle in.
Although Java Fern can take some time to show new growth, it will be unstoppable once it starts growing.
The good thing is that you can easily move this plant around when you want to change the décor of your tank.
3. Amazon Frogbit
The Amazon Frogbit is a floating plant that grows well in moderate to low light conditions. It provides shade and is a good water cover.
The Amazon Frogbit is a good choice for tanks with small fish as it encourages shy fish to swim and explore the upper regions of the aquarium.
Another benefit of the Amazon frogbit is that it derives carbon dioxide from air, not water.
So, it can grow alongside other plants that derive carbon dioxide from the tank water.
Elodea is a fast-growing plant that propagates through new shoots that appear on the main stem.
Consider adding it to your aquarium if you struggle with algae in your tank.
This plant will use up the nutrients in the water and force the algae population to dwindle.
Hornwort is a beautiful plant with needle-like leaves. It can be planted in the substrate or grown as a floating plant.
This plant grows from stem cuttings and is a fighter that needs minimum care.
The only concern is that you may have to inject carbon dioxide into your aquarium water when your hornwort population grows abundantly.