Believe it or not I just sat down and thought about giving you an update. My plants are now all very well and healthy, perky leaves, nice colour, the yellowish spots have disappeared. The pH run offs are still high but plants seem to be doing well regardless, although I will never use pebbles again! The one that had cupping on leaves and brown edges was doing a bit rough, I kept taking the bad leaves off but after few days of stable humidity it started recovering and growing new healthy leaves. My vocabulary isn't rich enough to find the right words to thank you for saving my amateur ass. You're a legend Myke!!!