potassium deficiency

this as far as I can tell is either a magnesium or potassium deficiency. I've added both to the feed but I am pretty sure I was feeding enough mg, I know I was feeding too little K to see if I could get away with it.

What's it in and what are you feeding it?

just posting the pic to show what a potassium deficiency can look like. Plants have perked right up after adding K.

Bottom line I have learnt is that all these deficiencies look so similar it is best to know roughly what the plant needs and work out how much of each macro nute you are feeding. then aslong as ph is right I can work out what's wrong. That's the theory anyway lol.

This site has been very useful for me

http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm