So what I thought was light burn I'm starting to think was actually nute burn? As it's started to do the same on budsites lower down the plant, but not to worry as I've started flushing now anyway, flushed through 20l of plain water the other day, I've actually cut one cola off already as it was about 50% Amber (and I'd ran out so thought perfect opportunity to test it) but that was the closest to the light. The rest have still quite a bit of clear but are getting cloudy by the day, so I'm thinking maybe another 7 days now. Buds still getting bigger :D