Bestplant, a pot plant nursery based in Poeldijk, the Netherlands, has several locations for growing Spathiphyllum and other houseplants. In 2024, their separate water systems have been combined into one centrally controlled network. Drain water is now being disinfected at a single location as well. For this purpose, three old heaters have been replaced by a new, even more efficient ECOSTER E unit.
Since 1994, Bestplant has been growing Spathiphyllum in the larger 17-27 cm pot sizes all year round. The ten-hectare greenhouse complex also has space for some seasonal products like Hydrangea and the exclusive Green Orange. Spathiphyllum is a houseplant with scientifically proven air-purifying properties. That quality, shared by several plant species, is being promoted with the “Air So Pure” label and on similarly named online channels.
“This distinctive characteristic is definitely a factor in Spathiphyllum’s popularity as a houseplant,” says Bestplant partner Laurens van Dijk to Ton van Dijk of Van Dijk Heating (no relation, Ed.). "That’s true for both the business and consumer markets. The main thing, though, is that it is a beautiful plant that doesn’t need a lot of special care.”
Laurens, who manages Bestplant jointly with Willem van der Voort and Patrick Zuidgeest, has seen the company grow from a modest nursery where he had a part-time job as a high school student, into an almost continuous tract of ten hectares of greenhouses, spread over two locations (originally five). “The company was founded by Patrick's father and uncle. It’s quite something that he was able to realize his growth ambitions through the purchase of several neighboring companies. This is also how the last expansion, which took place under the current management, was achieved.”
In recent years, the Bestplant locations have been merged into an even tighter whole. An important part of that process was centralizing the energy and water supplies. It was a major operation involving a lot of excavation, construction of hundreds of meters of new supply and return pipes, installation of more than 500 solar panels on business premises, and redesigning technical spaces.
The result is that all the crops and cultivation areas are now centrally controlled and fewer installations are needed. “It’s a leap ahead in efficiency,” says Laurens, summing it up. “One of the last jobs was replacing three older, smaller Ecoster drain heaters with one new larger capacity disinfector by Verkade Klimaat. Since Zuidgeest Sr. started using the first Ecoster thirty years ago, they have now replaced two generations of heaters. So you can trust that we like this way of disinfecting.”
According to the grower, heating is the most reliable method for properly disinfecting drain water that can contain many organic components. “With Ecoster we stay on the safe side, and we know that we are making Pythium, Phytophthora and Cylindrosporium harmless,” he explains. “These are the main diseases that threaten our crops in the root environment.”
The Ecoster E has been operational since mid-January 2025. “We deliberately chose a size bigger. In principle, this heater can disinfect 10 m3 of water per hour – more than we’ll need anytime soon. The benefit of this is that we have more leeway in the actual use. When electricity prices are low, it disinfects as long as water is available. When prices are high, we can wait and let the wastewater silo fill up."
For the actual disinfection, pre-filtration takes place in the unit and the water is slightly acidified to prevent limescale. Once the disinfection has taken place and the water has cooled down, lye is added to bring the pH back to the desired level for use as irrigation water.
“These are all automatic processes, which you do have to set up,” says the new user. “Other than that, you don’t have to worry about it much.”
Shortly after installation there were some minor malfunctions, which were quickly resolved by Verkade. Since the new Ecoster E is equipped with an internet connection, Ton van Dijk was able to monitor it online from Bunnik. “That was useful and eye-opening,” notes the supplier. "Since the locations are linked and the water treatment is centralized, Bestplant has chosen to collect the drain water in a mixing tank, and the Ecoster draws its water from that tank. Initially, when it drew in the water it created a vortex, which sucked in air and made the device malfunction. Verkade then lowered the suction point, and the problem was solved. All’s well that ends well. Even though our active input will rarely be needed, it is nice that we can tap in and monitor it, to troubleshoot and fix any defects.”