Corydoras sleeping under a small Cryptocoryne Wendtii leaf.

What Is a Root Feeder Plant: Definition, Species, Fertilization

What did you just buy from the fish store? Is it a root-feeding plant or a water column feeder? The terms are used quite often among fish keepers. And even though the distinction is somewhat artificial, it has practical applications.

It helps plan our tank layout, choose substrate, and fertilization method (if any).

To illustrate what a root feeder is, here’s a non-exhaustive list of the most popular species with powerful root systems:

  • Cryptocoryne
  • Amazon sword
  • Tiger lotus
  • Dwarf hairgrass (and other carpeting plants)
  • Blyxa Japonica 
  • Dwarf Saggitaria
  • Vallisneria
  • Ludwigia
  • Rotala

All these plants absorb nutrients from the water column too, but they develop large root systems and benefit greatly from enriched soil.

But let’s break down the term “root feeder water plant” in detail to better understand the role their roots play.

Definition of Root Feeding Plant

Let’s get one thing out of the way first.

All plants that have roots use them to absorb nutrients. Strictly speaking, all of them are root feeders. Conversely, absolutely all plants feed from the water column, too.

The thing is that amount of nutrients roots can procure differ greatly. And that’s not solely down to the plant species. Environmental factors play a massive role in determining how much nutrients the roots provide compared to the leaves.

I will get to the nuts and bolts of how water plants feed themselves in a bit, but before that let’s provide a working definition of a root-feeding plant:

Within the hobby, plants with powerful, large roots are called root feeders. They do great with local fertilization (root tabs) and thrive in a thick substrate. Root feeders can grow without fertilization, especially in an aquarium with fish whose waste will feed them.

Again, all these species feed through their leaves as well. Voraciously. Liquid fertilizers will also do them a world of good.

But root feeders need thick substrate not only for nutrition. Large plants like Amazon swords need powerful anchorage to stay put. Vallisneria and Saggitaria species spread through offshoots that go through the substrate.

Root-feeding species effectively clean the substrate and improve the water quality by extracting biowaste for their own needs.

And that’s not all.

How Water Plants Get Nutrients 

Water plants are opportunistic feeders. I know, they look like they are just hanging there, but in reality, they are dissolving particles like there’s no tomorrow. Being among the most optimized chemical processing plants in existence, they use everything they have to absorb nutrients: stems, roots, leaves, and flowers.

You can say that everything grows to eat and eats to grow.

If it grew, it can chew.

Nature likes circular systems.

Aquatic plants have a lot in common with terrestrial species, but they also have several major differences.

For one, the leaves of water plants are not as hard. To us, water is a very pressing force of nature, but for aquatic flora, it is a protective, nourishing embrace. Terrestrial species have seen some heavy biowaste and have developed unbelievable feats! Their aquatic cousins have it on the soft side.

Water carries a lot of useful elements that feed the plants. All species absorb a massive amount of nutrients through their soft leaves that are adapted to extract particles directly from the water column. Land species also feed themselves through their foliage, but their leaves’ primary function is to procure CO2 and sun energy. Food and water come from the roots.

Water plants use their leaves to get CO2, solar energy, and nutrients. The photosynthesis process is fairly similar but not entirely identical. And if the roots have access to nutrients, the plant will try to maximize their intake by developing the root system.

Do Root Feeding Plants Need Fertilizing Tabs or Enriched Soil?

Rood-feeding plants can grow in inert substrates without fertilizers, but they will definitely benefit from them.

Species like Vallisneria do better than others, as they feed through their leaves big time. But inert substrates like sand are devoid of nutrients only temporarily, as discussed here in greater detail. If you keep fish, their waste — poop, uneaten food — quickly penetrates the substrate and starts feeding the roots.

A successful tactic I use to maximize the exposure to nutrients without root tabs or enriched soil is placement. I plant the most demanding root feeders like Amazon swords in spots where waste accumulates. Such places exist in practically every setup as decorations and other plants block or divert the water flow to and from the filtering systems.

Also, a dense forest of low-lying cryptorynes will capture plenty of debris even in spots with stronger currents. See, these plants can be real crypts, full of dead matter.

Train your plants to become hunters!

All the same, if you plan to use fertilizers to grow fat, lazy plants, here are a few tips to help you make an informed decision.

Tabs vs. Liquid Fertilizers: What’s Best for Root Feeders?

As underlined throughout the article, even the so-called root-feeding plants get many, if not most, of their nutrients through the water column. Just like any plant in your tank, they will benefit from liquid fertilizers.

From a strictly nutritional point of view, it is hard to say which kind of fertilizer will produce better growth. If you have a mix of plants, some that lean heavily toward leaf feeding and more typical root feeders, using liquid fertilizer is a simpler way to boost them all.

The issue with liquid fertilizers isn’t their efficiency. There are superb products out there that your plants will love.

The question is whether your fish will be as happy. Liquid fertilizers impact the entire water column. An overdose can shift the balance and stress the fish out (you can learn to recognize the signs of stress if you have a few minutes to spare). What’s more, your plants will be unable to consume the higher dose, and then algae will bloom.

Another consideration is the regular input. Liquid fertilizers should be administered as specified by the manufacturer for best results. Irregular application only increases the risk of imbalances and algae blooms.

In comparison, root tabs are much easier to use. They can be applied only to plants with big roots, provide a constant release of nutrients, and last fairly long without affecting the overall water quality.

Their main advantage is the localized, stable effect.


Separating water column feeders (or stem plants, as they are often called) from root feeders isn’t as clear-cut as the terms make it sound. They are the two ends of a spectrum and even the same species oscillate between them, based on their needs and environment.

Cryptocoryne, a typical root-feeder will sate its needs from the water column if the substrate provides no nutrients. They can even grow like Anubias, attached to a rock or driftwood. A stem feeder like Bacopa will grow larger roots if planted in enriched soil.

Aquatic plants have evolved to be quite fluid feeders. They grow wherever the flow takes the nutrients.

Can root-feeding plants grow in an inert substrate?

Root feeders can grow in inert substrates like sand or gravel. Many consider gravel to be the better option for many species, but sand works fine too. Inert substrates accrue nutrients through fish waste and dead leaf matter. Additionally, all root feeders absorb nutrients through their leaves too, so a nutrient-rich water column will compensate for a poorer substrate.

Is Amazon sword a root feeder?

Amazon sword plants are heavy root feeders! They are the very definition of a root-feeding plant. They grow massive roots to anchor themselves but also to absorb nutrients through the substrate.

Similar Posts


Leave a Reply

Your email address will not be published. Required fields are marked *