OK - first off, apologies, as my digital cam isn't working...but I can describe the problem pretty well.
Set up - one female flowering for about ten days in an NFT system under 250 HPS, with an EC Meter reading of 1.4 consistently in both veg and flower. Water and grow-tent temps exactly where I want them. I change the water every 3-4 days. Plant generally looking in excellent health until about three days ago, when I noted bright yellow spots in the middle of just some of the leaves...not nute burn, as there is no curling or burning...yellow looks like bright yellow paint spots!
i'm thinking it's actually a nutrient deficiency, as EC read 1.4 yesterday and today read 1.3 and the ph went quite a ways up in less than 24 hours...so am I right in thinking that the girl is hungry? Am thinking of bumping up EC to 1.6 or 1.7...advice much appreciated from people who have confronted and overcome this problem, as otherwise the girl is looking great! most leaves a lovely green, and white hairs sprouting everywhere etc.