My appologies for no pics, parents borrowed digital camera.
Yep yellowing is starting from the bottom up
Yes leaves fully lellow and brown before they die, although they are wilting while being a bit green aswell.
Brand of soil - BioBizz Light Mix
[LINK]
The pots vary unfortunately 3 are 150x150mm square pots (all of these are affected)
3 are 200x200mm square pots (1 of these are affected, as the 2 newer plants arent affected at present - well startings but nothings turned proper yellow lol)
Nutes -
Bio Grow Liquid Plant Food [LINK] at 3 ml per litre
Ammonium Nitrate (NH4) - 4%
Nitrate (NO3) - 4 %
Phosphorus (P205) - 2%
Potassium (K2O) - 6%
Alg-A-Mic Vitality Booster [LINK] at 3.5ml per litre
Nitrogen (N) - 0.1%
Phosphorus (P2O5) - 0.1%
Potassium (K2O) - 0.1%
Calcium (Ca) - 0.2%
Magnesium (Mg) - 0.1%
Bio Heaven Plant Energy Booster [LINK] at 3.5 ml per litre
Nitrogen - .91
Phosphor - .18
Potassium - .24
Calium - .28
Magnesium - .20
Iron - .017
Manganese .001
Zinc - .002
Borum - .018
Copper - .0001
Molydenum - .0001
Anything else you need/can think of that may help ?
EDIT: Added nutes in bold as my formatting didnt go through to the actual post
EDIT 2: Added links for the nutes aswell.