The results of several tests concluded that Fiba-Zorb cannot be leached out and has good longevity during the culture of plants.
 

Nevertheless Turftech undertook research to prove that Fiba-Zorb did not effect the existing chemistry in the potting soil.
 

In 2000 the PBG in Naaldwijk investigated the effect of Fiba-Zorb on the fertilisers used in black and white peat respectively. To achieve this chemical analyses were carried out in duplicate. Half of the samples were rinsed. Water extracts were made by two methods: 1:1.5 volume extract (Sonneveld et al, 1974), and 1:5 volume extract (PrEN 13652, 1998). The obtained volume, determined with the 1:1.5 method, was rinsed with 4 times this volume with water. For the 1:5 method, the sample volume as a whole was placed in a cylinder and rinsed with 4 times the volume with water. A correction was made for the higher water content of the rinsed samples. In the extracts plant nutritional elements were determined.
 

The results of the chemical analyses of macro- and micro-elements for black peat and white peat treatments are shown in Table 1 and 2 below, using the 1:1.5 extraction and the 1:5 extraction, respectively. No effects were found on the nutrient concentrations of the extracts in either of the used extraction methods. As expected, the nutrient concentrations were higher in the 1:1.5 method compared to the 1:5 method, due to the more than 3 times higher amount of extraction fluid in the CEN-extraction. Rinsing lowered the nutrient concentrations in both methods, because during this procedure, nutrients were leached out. The higher EC and macro-element concentrations in black peat may be attributed to the higher addition of Dolokal extra.​