Kleinstrand Camping Resort, Jabbeke 

Severe bloom of blue-green algae (cyanobacteria), official swimming ban 

Jan Heus 
General Manager Campingpark Kleinstrand


"With OASE CyanoClear, we finally had a really effective solution for our blue-green algae problem. The experts at OASE offered us very clear and useful advice, rather than a lot of standard suggestions. Next year, we will plan ahead and will turn to OASE before the start of the season." 

Project highlights

After just 3 days, blue-green algae growth stopped and dangerous toxins were neutralised  
Safe lake usage was restored for holidaymakers, families and recreational sports 
A short time after the application of CyanoClear, visibility depth improved considerably 

The starting point

 The lake falls silent at the height of peak season 

The lake at Kleinstrand Camping Resort, located between Bruges and Ostend in West Flanders, Belgium, is usually a hive of activity during the summer: Families are enjoying their camping holiday, children are playing on the beach and in the water, and water skiers are racing through the waves at one of Belgium's largest resorts. But in mid-July 2022, the message was clear: Stop – official swimming ban! The reason? Cyanobacteria, also known as blue-green algae, had spread extensively across the lake, which can lead to a harmful concentration of microcystins. This was disappointing news for all users as well as for the operators of the campsite. The longest swimming ban since the opening of the lake inevitably led to economic losses. 

Blue-green algae: A survival artist that makes life tough for others

Contrary to what the name suggests, blue-green algae are not plants but bacteria, more precisely cyanobacteria, which occur in every body of water. These bacteria become a hazard when they spread suddenly and extensively as a result of increased phosphate content in the water and when water temperatures rise in the hot summer months. Blue-green streaks then form on the water surface and are often accompanied by foul odours. But above all, the blue-green algae produce microcystin – a toxin that is harmful to humans and can even be fatal to animals.  

The solution

Fast action is needed 

The official ban on swimming and lake usage meant a drastic restriction on holiday and leisure activities around the lake – with corresponding negative consequences for the surrounding tourism industry: Not only are the operations of the Adventure Aquapark and the water ski track reliant on the use of the lake, but the pollution in the water also led to economic damages for those responsible for the camping resort. There were a large number of complaints on the Facebook page, holidaymakers who had already arrived left the site and others cancelled their bookings. But the lake itself was also in danger: Cyanobacteria usually float on the water surface during an extensive bloom, taking light that is essential for photosynthesis away from plants living underwater. Dead plant remains form fermentation gases, leading to a drop in oxygen levels – and this can even cause the entire body of water to become biologically dead. In the interests of the guests, tourism operators and the natural environment, a quick solution had to be found to prevent further issues.     

Effective and innovative action against blue-green algae  

The local OASE partner made the appropriate recommendation after consultation with experts at OASE: CyanoClear, the new, effective and fast solution against cyanobacteria and their toxins. The innovative method of action impressed the responsible parties. The sodium percarbonate contained in CyanoClear releases hydrogen peroxide (H2O2) in a controlled manner when it makes contact with water. This destroys the blue-green algae directly through oxidation and simultaneously neutralises the toxins formed. The results are visible very quickly: The first effects can be seen just minutes after application, and within 48 hours the impact on the dangerous toxins takes full effect. The remaining flora and fauna remain unaffected because CyanoClear breaks down after the action phase into pure, naturally occurring decomposition products that are already present in the water. A fast and extremely effective solution against acute blue-green algae bloom. 

The successes

CyanoClear immediately created clear conditions 

Due to the urgent needs of the campsite, OASE was able to provide the required product quantities within a week and travelled to the site with a team of experts. Accompanied by extensive scientific studies before, during and after the treatment, they applied the exact dose of CyanoClear to the water by means of a special boat. In just a short time, they were able to observe that the typical streaks floating on the water surface were reduced and the visibility depth had improved considerably. After only three days, the blue-green algae bloom had almost completely disappeared. And the toxins? Analyses showed that CyanoClear had also successfully neutralised the harmful microcystins to 0.89 µg/l, thereby averting the health risk to humans and animals. The result was confirmed by the authorities: At the beginning of August 2022, the lake was officially open for use again – the summer, the lake and the swimming season were saved for everyone.  

Well equipped for the future 

The fact that the situation at Kleinstrand could be rectified so quickly was a huge delight for all campers and water-skiing fans as well as for the local tourist industry. Of course, future occurrences of cyanobacteria have to be expected, as longer periods of hot weather will continue to take place and encourage unrestrained blue-green algae growth. It is good to know that a fast, particularly efficient and demonstrably effective remedy is available in this event.


The Kleinstrand campsite will therefore plan for this in the future. Jan Heus, the operator of the campsite, also thinks this is a good plan and therefore has a positive outlook on the future: "In April of next year, we will be working with OASE to implement the application before the season starts, thereby keeping the operation open for the entire season. This means a lot less stress for us and more happy and satisfied guests". 


OASE CyanoClear

  • Fast, effective removal of cyanobacteria (blue-green algae) and cyanotoxins 
  • Breaks down after the action phase into naturally occurring decomposition products already present in the water 
  • Effectiveness successfully proven in practice 
  • Granulate for simple dosage and long-term storage 
  • Not subject to the regulation on maximum residue levels (EC) No 396/2005 

Project fact sheet

Project nameKleinstrand Camping Resort 
City/region/areaJabbeke (West Flanders) 
Type of waterFreshwater
Type and sizeSwimming and leisure lake, approx. 3.8 ha total area, 6 m average depth
ProblemExtensive bloom of blue-green algae, accompanied by harmful microcystin concentrations 
Product appliedCyanoClear
Period and type of applicationOne-off application at the end of July 2022
Result of the applicationApproval to open the entire lake by the local health authority on 2 August 2022 

In collaboration with:

OASE Professional Partner Aqua-Press, Varsenare 
AGL Engineering Office Börnert (Limnology and Laboratory) 

Do you have or have you recently had a blue-green algae bloom and want to deal with it quickly? 

Then get in touch with our consultants.