Vein on leaves yellowing?

[Captain Toker]

all sorted now. just bought 250ml of it. how best to apply, foilar feed or mix in with nutes / water at next feed?

Sweet : ) dilute it 1ml per litre and foliar feed, as iron says do it at 2 weeks old and again 2 weeks after flip (for photos) for autos just the 2 week mark should be ample.
15 minutes or so before lights on (or as soon as lights come on) and remember to raise your light as far as it can go until they dry otherwise the droplets will burn the leaves and ya don't want that!

[tlh2496]

thanks again captain. appreciated the help.