Grodan starting blocks 7.5x7.5x6.5cm

Starting blocks for 25/35mm plugs.
Substrate made of water-absorbable mineral rockwool. Ideal for pre-growing plants

The Grodan Delta starting blocks form the basis for a uniform and perfectly controllable propagation. The starting point for strong and healthy plant growth.

Stone wool is light, compact and relatively cheap. It has a high water retention capacity and contains a lot of air. Nevertheless, for a tropical plant, stone wool does have its instructions for use. A large proportion of growers grow too wet. This reduces the absorbable EC. This is fine for a growing plant, but not for a flowering one. The PH value of rockwool is quite high, around 8. It is therefore important to water rockwool well with a low PH (5.1-5.5), especially because the rockwool has a tendency to increase the PH value in the slab over and over again. Never set your PH below 5, your plant can stand it, but the rockwool cannot. It will lose its resilience and collapse as a result.