The REALM project brings greenhouse farmers and microalgae producers together

to help them overcome some of the biggest challenges they are facing today.


When Tiny Creatures Solve Big Problems

Wastewater treatment with microalgae. Click and watch.

algae culture
algae culture

REALM in a nutshell

  Farmers of soilless cultivation

need high-quality water to irrigate plants. They add nitrogen and other nutrients to the irrigation water so plants grow quick and healthy. The water that is not used by the plants runs off and is collected in drain water basins or tanks.

The farmers cannot directly reuse the irrigation water. It does not have the required quality, might spread plant diseases, and in the worst case destroy entire harvests. To discharge this drain water into the environment, greenhouse farmers have to comply with regulations and treat the drain water to decrease the concentration of the nutrients therein.

This is important because improperly treated drain water can add too many nutrients into the environment. If they accumulate in our rivers, lakes and oceans, nutrients like nitrogen and phosphorus can cause the excessive growth of plants or algae. This leaves too little oxygen available for fish and other aquatic creatures, creating ‘dead zones.’

High-tech equipment to treat drain water is expensive. Microalgae are great candidates to help clean the drain water in an economic and sustainable way.


Microalgae producers

can grow microalgae cost-effectively in the drain water from soilless cultivation, instead of using fresh water.

As the microalgae grow, they consume nutrients like nitrogen and phosphorous, removing them from the drain water and restoring the water quality. It then can be reused in the greenhouse or safely released into the environment. With low-cost open ponds next to greenhouses, the drain water can be effectively re-used as a free source of water and nutrients. Along with an automated cultivation system and the sun as the main energy source, the REALM cultivation concept is expected to drastically reduce the production costs of microalgae by up to 50%. When the production costs of microalgae are halved, innovative algae products can become cheaper, bringing the benefits of microalgae to everyone. As they only need sunlight, CO2, water and nutrients to grow, their products can be more sustainable than commercial agri- and aquaculture products

In the REALM project, we develop a new cost-effective cultivation approach to grow microalgae while also cleaning drain water and reducing the freshwater demand.



purifies water, replenishing our freshwater reserves and contributing an essential service to society and economy.

The natural water cycle is under great strain. Although industries slowly become more water efficient, the industrial demand for freshwater increases with the growing economy. This causes freshwater resources to decline – a situation intensified by global warming.

Industries like soilless agriculture and microalgae production need to redesign their processes to both reduce their freshwater demand and reuse water. When working together, these two industries can achieve this and perform the ‘ecosystem service’ of cleaning the water themselves.


Reduced water consumption by recycling and reusing drain water helps the soil to absorb, clean and store more water. This mitigates the scarcity of high-quality freshwater.


algae culture
algae culture

The impact of REALM on soilless agriculture, microalgae production, aquaculture and the environment.

energy consumption

At least
50% less energy consumption

in microalgae production

costs production

Less than
10€ production costs

for microalgae per kg dry weight

more biomass

Up to
30% more biomass






More than
8 new products

for agriculture and aquaculture


Less than
15mg/L of total nitrogen

left in the drainwater



directly from the air

In 2026
the REALM business model

will be ready for replication

Listen to the experts:

In REALM we want to revolutionise microalgae production. And while we are at it, also foster circular agriculture and a more sustainable aquaculture. How? Our microalgae producers, greenhouse farmers and aquaculturists will explain it to you.

More videos coming soon...

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