Right, time for an update...
At the time of the pics the 6 plants have been in ceg cycle for 17 days, I've been feeding them 300-400ml of 1.2-1.3 EC, 6.2 PH solution of Canna cocco A+B on a daily basis with the odd 6.2PH straight water flush.
Im planning on re-potting them into 3.5 litre...