5 weeks into 12/12 cycle and rapid leaf yewwowing occured and persists. Suggestions?

So, 5 weeks into the cycle and the yellowing started showing, firstly with the older leafs and now it progressed towards the younger ones and the tops.
im going organic , plagron batmix in 20 l container , which was recomended as enough nutes for 2 months of flowering. after the first month the older / lower leafes started yellowing kindof progressively.
so i assumed i had some nitrogen and potassium deficencies ( lower leaves withering and dying, purple leafe stems) and went on and got some Plant Magic oldtimer organic bloomer and used it along with GO(General Organics) bloom booster, additionally to some GO knettle brew and GO warmcast extract.
that seemed to have helped the situation somewhat , slowing down the progression of the yeellowing though the allready yellow leaves dont seem to rejunevate and green up rather still slowly progressing and dying out.
there seems to be no sign of overfeeding them, and they drink a lot of water up to 4-5 litres every 3 days, so what could it be?
nutrient lockdown? would they be still drinking if there was nutrient lockdown?
i cannot say that theyve been holding back with fruiting but up untill this moment they were green and frivolous now they are going all yellow
i got a couple of photos
plz help

Tough to tell from those photos, but heres a list of common problems that might help:

NITROGEN (N) Pale plants, red stems, smaller growth. Rapid yellowing of lower leaves progressing up the plant. Add any chemical fertilizer containing N. Treated plants recover in about a week.

PHOSPHORUS (P) Slow or stunted growth, red stems. Smaller leaves that are dark green. Lower leaves yellow and die. Add chemical fertilizer containing P. Affected leaves will not show recovery but new growth will apear normal.

POTASSIUM (K) Affected plants are usually tallest and appear to be most vigorous. Necrotic spots form on lower leaves. Red stems. Leaves appear pale or yellow. Add chemical fertilizer containing K.

CALCIUM (Ca) Lack of calcium in the soil results in the soil becoming too acid. This leads to Mg or Fe deficiency or very slow stunted growth. Treat by foliar feeding with one teaspoon of dolomatic lime per quart of water until condition improves.

SULFER (S) Plants suffering from S definciencies exhibit yellowing of new growth. Mix one tablespoon of Epsom salts per gallon of water until condition improves.

MAGNESIUM (Mg) Lower leaves yellow and may even turn white while veins remain dark green. Blades die and curl upward.

IRON (Fe) Leaves on growing shoots turn pale and veins remain dark green. pH imbalances make iron insoluble. Foliar feed with chemical fertilizer containing Fe or rusty water.

MANGANESE (Mn) Necrotic and yellow spots form on top leaves. Mn deficiency occurs when large amounts of Mg are present in the soil. Foliar feed with any chemical fertilizer containing Mn.

BORON (B) Growing shoots turn grey or die. Growing shoots appear burnt. Treat with one teaspoon of Boric acid (sold as eyewash) per gallon of water.

MOLYBDENUM (Mb) Yellowing of middle leaves. Foliar feed with chemical fertilizer containing Mb.

ZINC (Zn) White areas form at leaf tips and between veins. Occurs in alkaline soils. Zn deficiency can be treated by burying galvanized nails in the soil. Chemical fertilizer containing Zn can also be used.

OVER FERTILIZATION Causes leaf tips to appear yellow or burnt. To correct soil should be flushed with three gallons of water per one gallon of soil.