According to Cultilene, the 20 year-old dual density process is now history thanks to the arrival of Gradient Technology. Instead of placing two layers of rock wool with different densities on top of each other, it is now possible to 'seamlessly' increase the density of the rock wool from top to bottom. This play between gravity and suction results in a rock wool mat that is unmatched in terms of uniformity: Cultilene Exact Air.

Growing specialist Remy Maat from Cultilene: "Normally, the bottom 1.5 cm of a rock wool slab contains 95 to 100 percent water. Exact Air dries the bottom layer better, reducing this by ten percent. For most mats, the difference in water content between the bottom and top is 30 to 40 percent. With Exact Air, this difference is a third to a quarter lower."

Maat continues: "In tests, we observed 100 percent moisture content at the bottom of a standard slab three minutes after the drain started. With Exact Air, this was limited to 85 to 90 percent. There is currently no other mat that can do this."

The Exact Air slab has a horizontal fibre structure, which also contributes to good moisture and root distribution. In vertically-layered mats, the water-level dome takes the shape of the root mass. Exact Air, on the other hand, allows good root development throughout the mat volume. In comparative growing tests, more roots could be observed in the middle of the slab. At the bottom, the well-known large mass of inefficient water roots no longer formed and hair roots grew instead. These remained white throughout the slab.

Exact Air alternative for 10 cm high slab

Although Cultilene also carries a 10 centimetre high version for all mat types, this 'lift' is not necessary for lit tomatoes on Exact Air. In practice, the area expands further with 10 centimetre mats. The question is, what is this choice based on? If the choice for a higher slab is based solely on the desire to achieve a less wet bottom layer, then the Exact Air rock wool mat with standard dimensions is a good alternative.

On the other hand, Cultilene believes that the trend towards smaller and higher mats with the same substrate volume will continue. In lit growing, this helps to achieve a better plant balance. The reach of irrigation is also greater with this kind of slab.

But this is not to say that Exact Air does not also provide the desired added value in its 10 cm-high variant. The mat also delivers the smallest possible differences in the distribution of the water content, EC and pH over the total depth of the mat in this situation. The easy root development throughout the total rock wool volume supports a very good management of the water content and indirectly also the quantity of air as well as the EC and pH. So optimal control and management form the basis for optimum growing results. Exact Air offers extra help with varying sunlight during the spring and decreasing sunlight after the longest day.

For more information:
Remy Maat (Product and Application Manager)
T: +31 (0)6-83648588+31 (0)6-83648588) or
Ivan Casteels (Applications Propagation)
T: +31 (0)6-50631903+31 (0)6-50631903)

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