38 days into flowering

Ok so time for an update, i've had a few problems the last few days, the clone in the oxypot has been growing strange, it's started growing 3 fingered leaves and has some brown spots on it (the other clones i've transplanted to soil and they're doing well) I've checked the PH and it went from 6.0 to 7.0 in a few days (i know i should check daily, i've learnt my lesson ) i can only put this down to the hydroton, i thought i'd washed it enough and left it to soak in ph'd water for about 8 hours, i've adjusted the ph of the oxypot back down to 5.8 with the help of my new ph pen and put some more hydroton in ph'd water to change so i can swap it if i can't stabalise the stuff in the pot.

The plant in flowering that's having the problems with the yellowing leaves i'm pretty sure is an overwatering problem, i noticed a couple of weeks ago it was staying wet longer than the others and flushed thinking it might of had a nute lockout that was causing the yellowing (doh, just made the problem worse) After the flush i fed half strength nutes and the yellowing continued so i figured the feed needed increasing and fed again (it still ain't clicked i'm overwatering ) Made a right royal cock up of it, anyway now the pennies finally dropped i've had it out of the pot and put a fan on the mud to dry it out a bit, so here's hoping i can get it healthy quickly. The roots don't look too bad i was worried about root rot but if there is root rot it's pretty mild, i'm thinking about getting someting as a preventative/treatment just to be safe, i've done some reading and h2o2 or rhizotonic might be worth a try, what do you think?

Anyway enough bad news The other two plants are looking healthy enough. Had them out for a feed tonight, i'm feeding 3ml grow and 6ml bloom per litre. Here's some pics!