7.5cm Grodan Rockwool Blocks

7.5cm Grodan Rockwool Blocks Product Details:

7.5cm Grodan Rockwool Blocks are used to transplant your rooted cuttings or seeds into with the idea being to grow your babies to a suitable size before moving them in to your final pots or hydroponic system. These rockwool blocks are available with either a 25mm or 36mm hole to fit the two sizes of rockwool propagation cubes we sell.

Before using rockwool growing medium always pre-soak it for 24hrs in a weak nutrient solution (1 to 1.2 EC) with a pH of 5.2 to 5.5 and add a dose of Canna Rhizotonic if your budget allows. The pre soaking is important as rockwool has a high pH so by soaking it in a lower than normal pH it will stabilize around the 5.8 to 6.2 level you want for hydroponics growing.