my plants are 2 weeks old and i feed with canna nutrients aqua + 2ml rhizotonic + 2.5ml cannazym + 2ml mono CAL + 2 ml mono MAG ( it says 1-2 ml per liter of water ) i have phed my water after adding the nutes on one of the plants it looks like it has some rust ...it looks like calcium deficiency , which is wierd since i give 2 ml of CAL