top of page

Why Macro Nutrients play a major role in a Planted Aquarium?

Updated: Feb 1, 2023

Ever wondered as to why Macro Nutrients play a major role in a Planted aquarium. Co2 being a major component in an Aquarium , lack of macro nutrients or no macro nutrients at all can be disaster for your plants. Major disease stem out of having no macro nutrients and over use of macro nutrients or even micro nutrients can cause an Algae boom in your precious tank. For the purpose of this article lets focus on the importance of Macro Nutrients (NPK that is Nitrogen, Phosphorus and potassium).

As Human beings we require nutrients to live and grow , so do the plants require important nutrients both micro and macro nutrients to grow healthy. Macro Nutrients supplied in an Aquarium tank comes through various forms such as Co2, Fish Food and Fish waste. Plants do use them from these sources. Excessive macro nutrients can cause problems which can be harmful to fish. Its important to know the limits of macro nutrients supplied to the aquarium. Have enough plant to absorb the excess nutrients. Balancing of the nutrients come out of practise.

Lets talk about Phosphorus

Phosphorus plays an important role in healthy plants. Deficiency of phosphorus can be seen in yellowing of leaves. Plants are able to get enough phosphorus because of fish food and fish waste present in the water. Excess of phosphorus can lead to Algae.

If you have Green Spot Algae there is a possibility that your tank suffer from Phosphorus (P} deficiency. Green Spot Algae is a good indicator to take suitable action.

There are various kits in the market to test NPK level. We recommend test kits from Seachem which is very easy to use and give you accurate reading. One needs to take care not to exceed 3 ppm (part per million) of phosphates. It should be in the range of 0.2ppm to 3ppm. Excess of phosphorus can lead to Algae problem. It’s a smart idea to use this unit because plants don’t care what is the volume of water is , they are mainly concerned about how much is the powder or concentration is out into the tank. The measurements also depend upon the lights or any addition of plants to your tank. It keeps on changing , you will need to measure frequently the uptake rate, so that your plants will not be hungry anymore.


Low nitrates are always a problem with the beginners. When I was a beginner it was crazy idea of overdosing with nutrients. A real big cardinal mistake in my so called an enjoyable journey. When I look back I ask a question to myself why do I write the blog. The answer is to make the hobbyist aware of taking the right decision and to avoid fundamental mistakes in future.

What is the sign of Nitrogen Deficiency?

Classic sign is the old leaves turning yellow and translucent , espically starting at the leaf tips.

Sometimes , we are so emmersed into the dosing regime that we forget that the plants are growing up and we continue to dose in the similar manner. It becomes important to increase the dose of nutrients as plants grow or we need to propagate the plants.

But sometimes you have noticed that new plants leaves have become yellow or translucent, and just melting away, its not a sign that it suffers from Nitrogen deficiency but because the plant must be grown emmersed. Or sometimes the plant is grown submerged by an hobbyist , but when you try to grow it , it might melt away as it was grown in different water parameters and needs time to adjust to your water parameters.

Sometimes you will also find out that some stem plants loose the lower bottom leaves , but do not worry on this just cut the upper top of the healthy looking plant and grow back into the soil , so that you don’t see the skinny part of the plant. But, do cut only after you find the newly submerged plant have been adjusted to your water parameters.

Potassium Deficiency

Have you noticed small pinholes on your leaf surrounding the holes there will be a yellow ring , well then you have a potassium deficiency. This can be easily identified. Solution to this is to increase potassium deficiency.

We would like to recommend here seachem products while dosing the macro nutrients as well as micro nutrients . The instructions for an effective dosage is very clearly explained on the label. If you using a good soil like tropica which comes with nutrients in them then dose nutrients only after 2 months. Just don’t use any fertilisers. Tropica fertilizer can also be beneficial for the plants, if used according to the instructions.

I would like to sum up saying that whatever the plants you use in the tank, invest in proper test kits and do not dose according to your regime. You will have to change the dosage requirement accordingly as the plant grows. Also lights and Co2 play additional all play an important role in a healthy planted aquarium. Observe the growth of the plants, supply them adequate nutrients and propagate your plants. You will loose some plants and grow other healthy plants. Give some time for your planted aquarium to thrive into an healthy eco system, just don’t rush and overdose with nutrients as I did at the beginning which turned into an eco disaster. Just enjoy the Hobby while you learn on the way.

Seachem, provides all important Nutrients to the planted aquarium such as seachem flourish Nitrogen, Phosphorus, Potassium and all micro nutrients such as Seachem Flourish range of products. In India you can get at the following link all seachem range of planted solution. At we are always there to serve you with the best solutions from Seachem and Tropica. We do keep the premium range of seachem Products ( Aquavitro).

To buy in India, Please click on the image for NPK ( Seachem Flourish Nitrogen, Flourish Phosphorus, Flourish Potassium) click You can give us a call for all aquavitro range of products in India or drop an email at

Cheers! Stay SAFE!!


Author :- Sunil Dcosta at and at (Blog Site)

154 views0 comments


Rated 0 out of 5 stars.
No ratings yet

Add a rating
dog photo thai.jpg
bottom of page