Yellow Leaves. Help!

Hi there can any of you good people help me. i have got a yellowing problem on some of my plants and i cant pin point what it is.

i am growing in soil, water ph 6.8 - 7.
temp 78 - 82 f
5th week flowering
biobizz bio bloom,top max 5ml per litre. bioheaven 3ml per litre.
i was using biobizz bio grow but have now stopped.
1 tbl organic unsulpherd black-strap mollassis per 8 litres.
the last two waterings i also used 4 ml per litre of rhizotonic, but i have not been using any root nutrients during the grow. probably a mistake.
the last two waterings i airated the water over night with an air pump.
i water with nutrients 3 times a week. 1 litre per plant, 11 litre pots.
4 days ago i tried some superthrive. no change,
i have been told its a magnesium def but i need a second oppinion to be sure.

your time is much appricieted
tekno

you got the same problem i do im on a differnt nutrient setup the coco A+B with RHIZOTONIC, Cannazym and im lacking the boost and youre right that was stupidy on not using root nutrients how do u expect plants to grow? the plant doesnt make the roots grow the roots make the plant grow. I'm looking into a niitrogen defiency or probably a phosphate problem those are my two guesses right now. keep it up tho they look good and feed the roots the micros!

also a magnesium def. also between those three try to fix it and see what works!

i think your ok ......i dont like how u water but u got buds have u grown this b4 do u not normally lose some leaves at this time of life ..............cause they look happy ........?

I dont know where this J dubbin is coming from. You are in week five.
Like wayno said, it is natural for the plants leaf to yellow as the stored nutrients are used.
You are in soil, he is in coco, big difference as coco has zero nutrients to start with.

hi wayno.i have grown before but didnt water with nutrients 3 times a week only 2. i sometimes loose leaves but they dont normally go that colour.
which way do you feed. ?

yeh man next time feed the roots from the begining, lesson learned.
gonna grow super lemon haze nex time.