yellowing of leaves

[mattas]

i added some epsom salts at half the reccomended dose today to see if this helps the yellowing of the fan leaves,
the plant on the left in the pic is starting to look at bit more alive and seems to be developing bigger flowers ,so my not be as stuffed as i first thought or as the photo suggests,
as for the spider mites ,i have been checking daily and there doesnt seem to be any sign of them so may be my spray worked?
up to day 24 of flowering and seen the first signs of trichs

[stinkyattic]

Why does everyone think that Epsom salts are some kind of miracle cure!? There's NO evidence of Mg def; that is a straight lockout from over fert, and Epsom salts are going to make it worse.
'DON'T add more soluble Potash until you have ruled out other issues' does NOT mean add Epsom salt instead...
Your problem is that you are running a nightmare fertilizer combination that is inappropriate for flowering indoor cannabis.
Osmocote is a slow-release soil fert that is very difficult to work around.
Your blood n bone mix is completely wrong; flowering plants need LOW TO NO nitrogen and lots of phosphorous.
On top of that, the mix of a slow release soil fert plus an available fert is just asking for trouble- those plants are burned VERY badly from over fertilizing. You're supposed to wait until AFTER harvest to set them on fire....

They also would have benefitted from a transplant at the start of flower by the looks of things.

Tear off those drain trays on the pots and run 3 gallons of tap water throuhg each pot. Then feed with a correct BLOOM fert at 1/4 strength immediately.

You are close to harvest and will be going into your flushing time very soon, and if you don't flush all that crap out, NOW, your buds will taste disgusting and chemmy.

[mattas]

going to flush tomorrow, when you say blooming nutes is that a fert with both high p and k ? will potash not do?

[mattas]

just went and brought some gauno superbloom which has a high p,
this and the potash together should be a good combination?
plants looking healthier after flush and refert,