Planted Aquarium Fertilizer Guide – Keep the Greenery Spectacular

A planted aquarium is an excellent highlight. To do it the right way, you have to learn some basics. One of them is the utilization of fertilizers. This article will give you the knowledge you require to start utilizing fertilizers in the right manner. So, keep reading this planted aquarium fertilizer guide to learn about the right fertilizer use in an aquarium.

Once you decide to include plants in your aquarium, it is crucial to understand their basic needs and care requirements. Like humans need food to live, aquarium plants have specific nutritional needs.

If you are not providing them with that, they might stop growing or even die. If this is new to you and you find it hard to understand the needs of the plants you are putting in your aquarium, it is good to consult other enthusiasts online.

Once you understand your plants’ nutrient needs, this article will help you choose the right fertilizer for them. Here is a complete guide on all the things you require to understand about planted aquarium fertilizers.

Why do you need aquarium fertilizers?

Living plants are not like other decoration materials that you might put in your aquarium. They are living beings that require food to live and grow. Fish in the aquarium excrete waste, which functions as food for the plants but may not be enough.

If you want your plants to stay healthy, adding fertilizer has no other alternatives. Because in the wild, the resource of necessary nutrients for plants is vast. But in aquariums, they are limited, and so you have to provide it externally.

How do micronutrients and macronutrients differ?

You want to ensure your aquarium plants’ proper fertilization, so it is better to have some basic idea about plant nutrients. Most aquatic plants need various mineral nutrients to develop. These minerals can be divided into micro and macronutrients.


These nutrients are required for plant growth, but they are usually needed in minimal amounts. The micronutrients include Zinc, Molybdenum, Manganese, Chloride, Iron, Copper, and Boron.


Macronutrients are the essential nutrients that plants require in large quantities. These nutrients include Sulfur, Magnesium, Calcium, Potassium, Phosphorus, and Nitrogen. These nutrients are usually added directly into the water rather than to the soil.

See the impact of every nutrient on your plants:


It is among the essential nutrients required by both animals and plants. Plants utilize Nitrogen in the synthesis of proteins. Generally, pants get Nitrogen from fish waste, but it is not sufficient.

Biological waste decomposes to ammonia, nitrite, and nitrates. All these are nitrogen compounds and provide Nitrogen for plants. Still, you may have to add nitrogen-rich fertilizer to fill the gap.


Plants use Phosphorus to convert sugar into nutrients, and it is also crucial in the process of photosynthesis. Putting excessive Phosphorus in your aquarium can cause the growth of algae. So, it is crucial to maintain the right amount of it.


Potassium is crucial for plant growth. Therefore, it is needed in large quantities in aquarium waters. Potassium can naturally be present in the tap water but may not be sufficient for your plant’s growth. Supplements are the best way to provide sufficient Potassium for aquarium plants.


Magnesium is the central atom of the chlorophyll molecule. Chlorophyll presents in the green leaves and captures light for photosynthesis. So, Magnesium is the powerhouse behind the photosynthesis process. And it plays a crucial role in making plants green.

Naturally occurring Magnesium in the aquarium water may not be sufficient for plants. A fertilizer like Epsom salt, which contains Magnesium sulfate, serves as the additive for it.


It assists in chlorophyll formation and healthy growth of roots. Also, it enhances plant growth. Magnesium-sulfate-rich fertilizers provide Sulfur nutrients for your aquarium plants.

Non-mineral nutrients

Plants need other non-mineral nutrients, including Carbon, Oxygen, and Hydrogen. They are also vital for their survival. 

The market provides a wide variety of fertilizers that you can choose for your aquarium. This can make your choice challenging, but it should be a lot easier with the assistance of this guide.

The basics of fertilization

Now we know about macronutrients, micronutrients, and non-mineral nutrients. Fertilization aims to add macronutrients and micronutrients to the aquarium. Let’s start with some basics of fertilization.

The golden triangle

the golden triangle for plants

A golden triangle represents the driving force of plants’ growth. The light stays on the top of the triangle, while macronutrients and micronutrients are in the rest points. A balanced combination of these three is crucial for successful plant keeping.

Basically, light is the determining factor for how much macronutrients and micronutrients your aquarium will need. The more light you provide, the more nutrients are required. If the nutrient supply is limiting, it ensues slow plant growth. And if nutrients become surplus, it starts polluting the aquarium water and promotes algae growth.

Adding macronutrients

Among mineral macronutrients, Nitrogen (N), Phosphorous (P), and Potassium (K) are the most prominent. You can ensure NPK supplementation by adding fertilizers.

 CO2 is another macronutrient and can be added through a CO2 supplementation system.

Adding micronutrients

You can ensure necessary micronutrients for the plants by fertilization. Among all, iron and manganese are the most vital micronutrients. Liquid fertilization and mineral-rich substrates are the best way to add them.

The dosing approach (what path should you take)

I’ve experienced that maintaining a planted aquarium is a bit tricky job and needs some expertise. Still, you have to start learning at a point. Here I tried to explain the ideal fertilizer dosing approach.

The dosing approach you take depends on the type of aquarium you have. Using high doses of nutrients in a sparsely planted tank causes instability. If algae are introduced or triggered, the high nutrient dosage can escalate the problems.

On the contrary, if you have a tank that is full of nutrient-hungry plants and are using a lead dosing approach, plants can deteriorate or starve, and this causes algae to develop too.

EI & ADA dosing

Below, I will compare the two most common dosing systems on opposite sides of the scale:

Estimated index (EA):

The Estimative Index (EI) utilizes high levels of nutrients that are put in the water column. The EI approach is designed to provide non-limited growth for aquarium plants.

The philosophy behind the strategy is that when plans are healthy and have the nutrients they require, they will out-compete algae in your aquarium.

Aqua Design Amano (ADA):

The Aqua Design Amano (ADA) uses nutrient-rich substrates and lower levels of water column nutrients. The ADA approach is designed to provide plants with slower growth rates and lower maintenance, which means it is simpler to attain aquarium stability.

Leaner dosing

Generally, a leaner dosing strategy is excellent as it does not require much pruning and provide better tank stability. Fewer nitrates also manifest the reds in some plants more apparent. You should somehow moderate concentrations of nutrients in your tanks.

You should use a minimal dose if you are growing smaller carpeting plants in your aquarium and a high dose for dense stem plants.

However, flexible plants can grow in different levels of nutrients. Complete but lean dosing approaches just mean that your plants grow at a slow rate, and this is the recommended method for beginners because it can be controlled easily.

leaner dosing fertilizer for aquarium plants

Soil substrate

The amount of fertilizer you use can help in providing your plants with a controlled growth rate. You should utilize soil-based substrates in your tanks apart from the regions that need cosmetic sand.

Aquarium plants often grow more stable and better in soil rather than on gravel or plain sand. The nutrients on the substrate can also be consumed by hungry plants during a lean dosing approach.

Why should you choose to grow aquarium plants slowly?

The primary reason is less maintenance and less pruning – these are common weak points for amateur aquarists. Plant growth is a simple task, but most people hold back on pruning to a level where over-crowding breaks their tank.

The aquarists postpone trimming over and over, and when they do prune, the plants are not in a good state of health because of overcrowding. This maintenance instability causes persistent problems concerning algae or only some short-term stability times where the aquarium looks good before it becomes overcrowded again.

Having your plants grow at a uniform, the slow rate is excellent for the overall stability of your tank and is highly useful for sustaining a similar look for similar aquariums that need plants to remain at a particular area or height.

There is a misconception that a richer dosing strategy gives richer colors to plants. People believe that the more nutrients, the redder your plants will be.

There are several species that of plants that turn red when they are provided with low levels of Nitrogen, and these plant species will never become red when provided with higher doses of plants.

Choosing the right fertilizer for your tank

There are many factors that you should consider when investing in your aquarium fertilizer. They are very crucial for beginner planted aquarium enthusiasts. So, here is what you should consider:


What is contained in your fertilizer is very crucial. You should choose a bioproduct or a product that is as natural as possible.

Some fish and aquarium plants do not respond well to some chemicals. And even if the side effects do not appear immediately, your plants will eventually be exposed to great dangers and possibly even die.


Aquarium fertilizer is not a one thing product, so you should choose one that suits your budget over a prolonged period. But it is not wise to compromise the quality for the price. I’ll advise checking user’s reviews before buying it.

Manufacturer’s guide:

Manufacturer’s instructions are handy when it comes to adding fertilizer. An excellent fertilizer comes with straightforward instructions that guide the user on how to use it correctly.

It should also include the manufacturer’s contact information for reaching them if you need further information. Without instructions, you may be left to make several changes when utilizing such products.

So, always ensure that you have the correct information on how to use your product.

Related Topic: 10 best aquarium plant fertilizer for your planted tank

How to utilize fertilizer to increase efficiency

If you have the fertilizer you require, you have to utilize it the right way. Luckily, most planted aquarium fertilizers come with instructions that will assist you with the dosage requirements depending on the size of your tank.

However, there are some rules that you need to follow, regardless of the type of fertilizer you are utilizing:

How to utilize fertilizer to increase efficiency

Do not overdose:

You may be tempted to use more than the recommended dosage, discerning that it will stimulate faster plant growth. If you add more nutrients to your water column, your plants cannot consume it all, and it can promote the growth of algae. So, only use what your plants will consume.

Consider fish safety:

Most fertilizers will not cause harm to your fish, but there are various exceptions. In general, if you utilize natural products, you should not worry about the animals’ safety.

But it is still advisable that you check and see if your invertebrates or fishes are compatible with the type of fertilizer you are utilizing by reading the instructions manual or contacting the fertilizer manufacturer.

Remain consistent:

You should choose a product that works well for your aquarium and stick with it unless you have a convincing reason.

You might be tempted to try a wide range of products, but you should try that in a different secondary tank and try not to intrude on the balance you have developed in your primary tank.


Choosing the right fertilizer for your planted aquarium can be challenging, but it is a crucial step for a beautiful planted aquarium. The correct choice can considerably enhance your plants’ growth, while a wrong decision can drastically damage them.

After choosing the right fertilizer, you have to dose it correctly. Only an accurate dosing technique can help to attain the goal.

However, by reading this guide, you should be able to make everything right.

Sujit Modak

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