Top fan leaf issue

Hey guys.
My grow has gone well upto day 43 of flower.
Grown in soil john innes #2 which is a UK ph soil of 6.0-7.0 and as you can see ph sitting at 6.8.
Started using ff nutes from week 5
Ive noticed yesterday a couple of top fan leaves yellowing with brown spots
Its a pineapple express auto, now is this a calcium issue or is a show that the plant is coming to an end.
Ive posted pics for you to take a gander at.
Any help appreciated with no sarky comments please.
Thanks

Not a fading look. Might be calcium deficiency or a low soil PH. I don't find those soil testers useful for PH. Maybe others have confidence in them.
You know the drill, more info.
How big are your pots?
How often do you water?
How often do you water only between nutes?
How much water do you use?
What % run off do you have?
What FF nutes are you using and what quantities?
Temp and humidity?

I'd guess calcium, but unclear if it is locked out or just not available.

Bugeye said:

I'd guess calcium, but unclear if it is locked out or just not available.

Click to expand...

Should i flush?

I wouldn't flush, John innes soil turns to clay when you put too much water through it!

Personally I'd go with 0.5ml cal mag per 1 litre, ph'd to 6.3. Give it enough to get 10% run off.

Ok cheers for that

Analog soil PH meter does nothing for letting you know what PH you are " feeding " her.

You must dial in PH of your water and of the feed mixture you give her. Analog meters swing widely in accuracy anyways. Get a digital meter and TEST water and feed , that way you can adjust up or down.

This why you are having issues.

Budzbuddha said:

Analog soil PH meter does nothing for letting you know what PH you are " feeding " her.

You must dial in PH of your water and of the feed mixture you give her. Analog meters swing widely in accuracy anyways. Get a digital meter and TEST water and feed , that way you can adjust up or down.

This why you are having issues.

Click to expand...

Yes to be honest i need to invest in a digital..
Many thanks for your input