Hi Italian
Let clarify my post about rockwool .
Rock wool is unstable when it comes to PH the reson to soak them in water at the corrcet PH is to make them more stable, I soak mine in PH water at about 5.5 to 5.8 overnight and then let the exsess water drian off before use.
Rock wool is a good media for holding moistere so dont over water.