sick sick sick could i have some help please

[danger nhb]

hello there if some one could help me out here would be grateful,where do i start i am three weeks into flowering my fan leaves was the first to start turning yellow ,i am on NFT under 2 x 600w plenty of extraction temp 27 ph 5.9 EC at 17 .i have flushed as i thought i might av over fed them and they have got progressively worse since , only other thing my tank temp dropped below what it should be i am stumped as been doing big bud superskunk for a year now and nowt has changed so if there someone to help would be very grateful REGARDS DANGER NHB

[Stone]

If your EC was 17 they would have been dead long ago! :-)

If it was actually 1.7 and you flushed them they're most likely hungry.

Give them an EC of 1.9 - 2.0 and they should be OK.

[danger nhb]

yo stone ya right 1.7 up too 1.9 still the same after 3 to 4 days cheers stone anything else prob

[Stone]

The yellow won't go away after feeding them. If the overall yellowing process doesn't advance too much more you're probably OK as during flowering it's not too unusual to see the lower fans start to yellow.

[will_i_am]

...when was the last time you calibrated your pH meter? ...just wondering.

[danger nhb]

got two meters both them fine i am stumped as not changed nowt only thing think is intake changed from last time but are they symtoms of stomata ??????