News » 29.08.2025 - Growing like a brewer: why resilient cultivation requires a new cultivation system

Over a decade ago, Water IQ International discovered its strength in breaking down pesticides in wastewater from growers. The company, at the time a specialist in supplying water treatment systems for breweries, found itself so proficient at its craft that they decided to expand into horticulture.

"That small step turned out to be a big one," says founder and director Freddy Dekkers with a smile, speaking after his return to a horticultural trade fair for the first time in years. At GreenTech Amsterdam, Water IQ International presented several new innovations, a highlight of which was the BioNIQ filter, a strong but easy-to-use system that removes nitrogen and phosphate from water and is already performing well in practice. The Dutch company is also developing a completely new cultivation system.

After proving their technology worked for pesticide breakdown in greenhouse water, growers were quick to start using the first installations. But Freddy wanted to go further. "It's not just about removing pesticides from water," he explains. "I want to help growers raise stronger crops that don't need pesticides at all."

Kirsten and Freddy Dekkers at GreenTech Amsterdam 2025

Getting the right substances to the roots
In recent years, Water IQ International, now based on the university campus in Wageningen, has carried out extensive research into resilient growing methods. It all started with adding organic compounds to water. Measurements quickly revealed that the level of functional organic matter in horticulture was often "a hundred times lower" than in beer brewing, even though breweries also work under strict hygienic conditions to produce a food-safe product, just like growers do. So, could horticulture be done differently as well?

"During trials with young plant growers, we immediately saw the effect of adding functional organics up to a certain level," explains founder Freddy Dekkers. Plant growth accelerated so much that sometimes even the lighting strategy had to be adjusted. But transferring these experiences from propagation to production growers turned out to be tricky. Propagators often use ebb-and-flow systems, while most production crops do not. "In production systems it was difficult to get the right compounds to the roots at the right moment," Freddy says.

Fundamental research and ambitious goals
That challenge became the reason for Water IQ International to design its own cultivation system with an integrated water treatment unit. Not because the company aims to mass-produce growing systems, but to deepen knowledge about resilient cultivation. At their Wageningen facility, they can carry out full microbiological analyses on crops grown in this system, and when needed, they can lean on their neighbors at the university for even more advanced testing. "What growers need most is knowledge," says Freddy. "In many crops, growers run into similar problems, so the research we are doing is quite fundamental."

As water treatment specialists, Freddy and his team always look beyond the water system itself. "Our solutions have to work optimally within the entire growing system." That's an ambitious goal, he admits, and one that has often proven challenging in practice. "In field trials with production growers, we couldn't always detect the added compounds at the roots, yet we often saw a surge in opportunistic microflora instead."

Re-evaluating practices
In Wageningen, the team now runs a small-scale setup resembling an ebb-and-flow system. "One of the crops we are studying here is spinach grown on water," says Freddy. Spinach was not chosen by accident, it's a crop with notorious challenges worldwide. Many growers point to root exudates as the culprit. Freddy has a different perspective: "Root exudates are often treated as waste, but I don't agree. You should value them. They play an important role as signaling compounds for plants, triggering the right bacteria. Plants live in symbiosis with these microbes."

That is why Water IQ International is currently focusing on hydroponic crops. After all, water quality management is their specialty, and it's easiest to control in water-based systems. "Even with rockwool, which is considered an inert substrate, water quality is harder to manage. And if you switch to organic substrates, it becomes even more complex," Freddy explains.

Take fruiting vegetables grown on rockwool, for example. The common practice is to saturate the slab with water at the start of the crop, then wait, cut it open later, and see what has happened. "From a biotechnological perspective, that's a very strange process," Freddy remarks. Things get even more challenging with organic substrates: "The more organic compounds you introduce, the more crucial water treatment becomes, but also the harder it is to keep the right balance."

Cultivation system ready for a different organic substrate?
Right now, a big shift is underway in pepper cultivation, as growers in Europe and also Canada and the United States are moving from rockwool to organic substrates, partly due to plant losses in recent years. Listening to Freddy's story makes one wonder: are growers adapting their entire cultivation system to match this substrate transition? In most cases, the answer is no. They adjust their water treatment system, but not the whole cultivation setup.

Some growers on organic substrates explore alternatives like heating or ozone treatment for water. Freddy sees more promise in heating and is cautious about ozone. "Ozone reacts with many compounds. In an organic substrate with high microbiological activity, that can trigger unwanted reactions, potentially harmful for the plants."

Don't do what you wouldn't do in your home toilet
Freddy's general advice to growers is simple: measure first. "Know your growing system before making changes." In practice, that doesn't always happen. Baseline conditions aren't always clear. That's exactly why Water IQ International now conducts its own trials with its own system.

"In fact, we could revisit some of the knowledge from old textbooks of the 1960s, on soil and soil fertility. Look at soil-grown plants: their roots look completely different, and the plants are much more resilient. That knowledge is still valuable. We skipped a few steps when moving to soilless growing, and now we're catching up." At GreenTech Amsterdam, Freddy and his team noticed strong interest in their research and system. "There's a lot of enthusiasm for resilient growing."

For growers who don't want to wait for a brand-new system, Freddy already has some tips. "Start with something simple: take a fresh look at how you store dirty water. In horticulture, dirty water often sits in storage tanks, but at home, you wouldn't do that with your toilet either, would you? Avoid storing dirty water and treat it immediately instead. That way you give opportunistic pathogens no chance to multiply."

On the clean water side, there's also room for improvement. "Make sure there's enough circulation, not only during irrigation, but everywhere. With drippers that can be a challenge. Maybe we should ask ourselves whether we always need to work with drippers in the first place."

At GreenTech Amsterdam, Water IQ International also showcased BioNIQ. With this system, which enables the breakdown of nitrogen and phosphate in water with the help of bacteria, plant grower BPK, among others, achieves good results. Freddy expects interest in the Netherlands to increase as a new water purification deadline approaches in 2027.

In response to increasingly stringent water purification requirements for horticulture, Water IQ International introduced the Opticlear Diamond. The system is designed to disinfect effectively with minimal oxidant input while preserving organic signal substances.
 

 

Source: www.floraldaily.com

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