Fill a bucket with dechlorinated water, add a cup of worm castings, 1tbsp of epsom salt or Cal/Mag, ph it to 6.8, and bubble it with a fish pump for a day, then water your plants with it.
That looks like a slight magnesium def, or maybe a nitrogen lockout.
None the less if its not magnesium is a ph thing...
It dosent look to bad tho aslong as it dosent progress to more leaves.
Check the PH.
The brew I said to make will probably fix it, and if it dosent, it wont hurt anything, I promise. Plants need quite a bit of magnesium, Cal/Mag should always be included in your stash of fertilizers.
Its pretty difficult to od a plant with magnesium so dont hesitate to add a little to your water every time you need to water your plants.
Dont add more Maxi yet! Its always better to under feed than over feed. Maxi is a phosphorus and potassium fertilizer so youre probably going to have either a Nitrogen def or Magnesium def if anything.
But dont add Nitrogen if you are about to flip to flowering or if you are currently in flowering, it will weaken your stems and your nugs will be airy and not dense.
A few more, better detailed pictures would help too.....
....Anywho, keep us posted
