Green Crack Auto Slow Growing too Yellowish

Coir has no nutrients, you need to start feeding from virtually day one with a weak solution of "grow" formula with N/P/K........... root bulder does not provide any nutrition, it is just a stimulant. The addition of Cal/Mag is also needed in coir, also from the first week onwards. Coir is very free draining and the addition of perlite is generally not needed.

coir is void of nutrients and if its not buffered and processed right it will take all the avilable Mg and Ca and then release a good ammount of Na and K. Also you need to feed from day one with coir as it does not have any nutrients in the soil. Its also a good idea to mix in 30% perlite to help with drainage and prevent root rot from an over sasturated medium.