What is Aquarium Plant Food?

What is Aquarium Plant Food?

If you want your aquarium plants to thrive and grow efficiently, provide them sufficient food and other requirements. Here are the nutrients you have to provide your aquarium plants in the tank.

What is Aquarium Plant Food? Aquarium plant food is the nutrients that your plant requires for its survival and growth. Their absence and deficiency lead to the improper growth and death of plants, deteriorating your tank environment. Usually, plants absorb these nutrients from many existing sources in the tank, but you have to provide both micro-nutrients and macro-nutrients from external sources as well to them. 

What is Aquarium Plant Food?

Live aquarium plants are vital in an aquarium as they create a natural beauty in the tank and resembles the natural habitat of fish.

They promote a healthy ecosystem in the tank and serves a lot of functions in your aquarium. You can not establish an aquatic ecosystem in the tank without these beautiful and stunning living organisms.

Plants help nourish your tank fish with adequate oxygen and prevent toxicity by removing carbon dioxide from the tank if you add the proper amount of aquarium plant food. They help in the elimination and prevention of algae growth by removing nitrates and phosphates from the water.

They help to lower the stress and boosting the immunity of your tank fish. Feeding the tank plants is as essential as feeding other inhabitants of the tank.

Like other living organisms, these aquarium plants also require macro and micro-nutrients to survive. They can not thrive without proper and adequate nutrition.

Along with a good diet, plants require favorable conditions to grow and perform these beneficial functions. You can not neglect their basic needs unless it causes harm in the aquarium rather than benefits.

What nutrients are essential for aquarium plants?

Aquarium plants require macro and micro-nutrients along with other tank conditions for optimum growth. These nutrients are:

Nutrients Type Internal source External source Essential
Nitrogen Macro Tapwater Fertilizer Yes
Phosphorus Macro Fish waste Fertilizer Yes
Potassium Macro Fish waste, uneaten food, and tapwater Fertilizer Yes
Calcium Macro Tapwater and limestone rocks Fertilizer Yes
Sulfur Macro Fertilizer Yes
Iron Micro Fertilizer Yes
Magnesium Micro Fertilizer Yes
Trace elements


Micro Fertilizer Yes


These are the nutrients that your aquarium plant require in relatively large quantity, such as nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur are essential macro-nutrients. The micro-nutrients make up 96% of plant mass along-with carbon.


Plants absorb nitrogen in several different forms, and the most common are ammonium (NH4+) and nitrate (NO3-). It is the essential nutrient that your aquatic plants need. They require nitrogen for the growth of stem and leaves, and also it is a necessary part of chlorophyll.

Aquarium plants can quickly get new sources of nitrogen. Their deficiency limits and slow the growth and result in red coloration. Adequate concentration is around 10 to 25 mg/l NO3. This also helps to plant carpet seeds in an established aquarium.


The second essential nutrient your plant requires is phosphorous, and plants absorb them in the form of phosphates. The nutrient is necessary for the growth of flowers and fruits, and it is critical for plant processes where it uses energy.

Your colored aquatic plants may turn pale in the absence of phosphates. Also, typical signs are slow growth and decreased size shoot tips. Adequate phosphate concentration id around 0.1 to 1 mg/l. however, it is quite reactive and interacts with other nutrients


Potassium is the third essential nutrient, and the plant derives it from potassium oxide (a water-soluble form). It uses potassium for the growth and strengthening of the roots, leaves, and growing points. The optimal concentration of potassium is about 5 to 10 mg/l.


Aquarium plants require these micro-nutrients in small quantities, but they are essential for plant growth. The most common nutrients are iron, manganese, chlorine, copper, boron, molybdenum, cobalt, nickel, and many others. They make up about 0.08% of plant mass.


Aquarium plants require a sufficient amount of iron as it is an immobile nutrient that does not transfer from old leaves to new leaves. Despite its role in promoting coloration and pigmentation of the leaves, their excess does not enhance additional color.

Though their deficiency may result in yellowing of new growing plant leaves and stunted growth. Ideal iron concentration is around 0.05 to 0.1 mg/l.


Magnesium is the necessary element of chlorophyll. It provides a beautiful, bright green coloration in the leaves. You have to add the required amount of magnesium.

An element like calcium is necessary for cell wall formation and cell permeability. Sulfur helps to make amino acids and coenzyme. 

Trace elements

These trace elements such as boron, copper, molybdenum, cobalt, nickel, and others are essential for aquarium plants, but the plant needs them in very minutes quantities. Chlorine helps in osmosis and ionic balance.

 Copper and zinc are essential for the activation of some enzymes, and molybdenum help in nitrogen metabolism. Boron is helpful in calcium utilization, nucleic acid synthesis, and membrane integrity. 

Sources of nutrition for aquarium plants

Plants usually absorb nutrients from the tank water through their leaves and roots. These nutrients come in the water from fish wastes, uneaten food, tap water, and when you add fertilizers. Also, the fish tank substrate provides many nutrients to the plant.

Tap water

Tap water usually contains some chemicals, which is a source of food to the aquarium plants. Mostly it contains micro-nutrients such as magnesium in considerable amounts. Tap water of some regions also contain potassium but not in all areas.

It depends upon the place where you live. Checking the hardness of water helps you identify the number of nitrates and phosphorus in it, although they are in minute quantity. 


Tank substrate is the most important source of essential elements, especially the anchored ones. They absorb all the nutrients through their roots that are in the substrate.

Although soil is the best substrate for this purpose because it is rich in nutrients and plants better absorb it. You can also leave the aquarium plants in the pots for better results.

Fish wastes

Fish wastes provide the plant with the essential macro-nutrients that is why there is no need for extra food from external sources for most plants. Fish wastes supply a significant amount of nitrogen and phosphorous.

Larger fish produces more wastes, while smaller fish produces fewer wastes. Also, uneaten food serves phosphates and potassium to your tank plants.

What are the Aquarium Fertilizers?

The external source of food and nutrition for aquarium plants are fertilizers as they contain an adequate amount of the nutrient that a plant needs. For efficient growth, they require additional nutrition, and fertilizers are the best choices for them.

Most elements are already present in the tank, but you have to provide some additions such as magnesium, sulfur, potassium, and phosphate.

Fertilizers are the mix of all the essential nutrients that your plant needs to thrive. They can not get sufficient amounts from other sources.

Although fish wastes, tap water, and substrate provide nutrition but not in optimal concentrations. You must add fertilizers to the tank for rapid plant growth. By not adding fertilizers, you are starving and destroying your plants due to the lack of essential components.

Some best aquarium plant fertilizers

Some of the most common and suitable plant fertilizers are:

  • Seachem-flourish root tabs.
  • Seachem-flourish aquarium fertilizers.
  • All-in-one thrive aquarium plant fertilizer.
  • AiO thrive+ aquarium fertilizer
  • Thrive root capsule fertilizer
  • Osmocote plus plant fertilizer

Types of aquarium fertilizers

There are different types of fertilizers depending upon the nutrients, type of water, and plants.

Substrate fertilizers

These are nutrient-rich, soil-based substrates that ensure the adequate amount of all the elements enough for the plant.

It is a commercially-prepared soil additive that you can place around the plant roots. For the plants that have a dense root system, substrate fertilizers are best for them.

Tablet fertilizers

These are slow-release tablets or capsules that provide additional nutrition. They are cheap and inexpensive but do not use them as primary sources.

They slowly release nutrients that that plants can directly absorb. They are root tablets that you have to place in gravel or sand near the roots to supply nutrients.

Liquid fertilizers

Liquid fertilizers are more expensive than solid ones but are more efficient and absorbable. The plants can easily absorb the components through water, especially the stem-feeder floating plants that do not have roots in substrate.

The optimal dose of fertilizers for aquarium plants

The accurate dose depends upon the amount of light and carbon dioxide, number of plants, kind of fish, number of fish, tank size, and photo-period of your aquarium. There is always a recommended dose on the fertilizers pack that you are adding.

Remember, you can not rely on the written dosage as it may be less or more for the number of plants in the tank. Both deficiency and excess are harmful, so look for accurate dosage.

When there are few plants in the tank, add half of the written dose and when there are too many, add a little more than the recommended dose.

How often aquarium plants need fertilizers?

It is preferable to add fertilizers at an interval of two weeks at least and observe the growth of the aquarium plants. It is better to add in the morning time because of the photosynthesis process, so the plants absorb most of it.

Also, fertilize less often when the temperature is below 70 degrees F, and fertilize more often once the water temperature is above 80 degrees F. It is because the growth rate is slow in a cold environment, while it is faster in warm.

Other requirements of aquarium plants


Appropriate lighting is essential for the process of photosynthesis, and a plant can die in its absence.

Provide an adequate amount of light using LED lights, and it is better to provide about 10 to 12 hours per day. If using a fluorescent bulb, change them every 12 months for the best light output.

Carbon dioxide

Plants use carbon dioxide as fuel in the process of photosynthesis to produce oxygen. You have to provide sufficient carbon dioxide in the tank.

It is preferable to use carbon dioxide injections to promote plant growth. Some plants require 10 to 15 mg of CO2 per liter and, some plants need about 15 to 30 mg per liter.

Water quality

Water quality is necessary for the growth and maintenance of aquarium plants. Proper water parameters, chemistry, and circulation help fasten the growth rate of plants.

It ensures an efficient supply of required components and inhibits algae growth. Change one-fifth to one-third of tank water at least after two weeks and maintain water hardness.

Deficiency and excess of nutrients for aquarium plants

Unbalanced and inadequate nutrition can lead to several deficiencies that ultimately result in plant death.

Nutrient deficiency impacts aquarium plants’ growth rate and coloration. You will observe stunted plant growth and dead leaves that fall apart in the tank.

Excess nutrition promotes algae growth and results in its outbursts and is hazardous for both plants and fish in the aquarium.

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