Hopefully things are going better for you... assuming you're using good quality nutrients I wouldn't understand why you're seeing this so early on. Typically when I see problems like this, I simply flush the plant with a low strength mix of base nutrients only. By low strength I mean NO MORE than 1 ml per liter of water of A and B. If you're meausring the PPM of the mix, you should be somewhere around 350-450 ppm with the solution you use. Put enough in the plant to get run through and remove the excess from the drip pan on your planters. Curious, why do you have expanded clay pellets in the pots?

One other suggestion.. kick your Ph up to a range around 6.1 - 6.3. Being to acidic can also cause uptake problems.

Peace,

Farmer Rich
Farmer Rich Reviewed by Farmer Rich on . Something wrong but I don't know what Could any please give me some advice please, I am currently growing 10 plants under two 600w metal halides, the are in 15 litre pots with canna coco I am feeding ph 5.5 Canna coco a&b 10ml per 10 litre of water Rhizotonic 20ml per 10 litre of water. Rating: 5