Magnesium deficiency? anyone know whats wrong with my plants

Is this Magnesium (Mg) deficiency or something else please help me,(pic 1)
I also have red fan leaf stems on one of the other plants,(pic 2) Phosphorus(P) deficiency?
I am using ionic bloom nutes with no other or supplements.
They are under (left to right pic 3 150w hps, 125w envirolite flowering bulb, 150w m/h)the front left is the one with red stems and the front right is the one with bad leaves mainly on the bottom of the plant.
i am only using 4ml of nutes per litre of water.
should i get some epsom salts?
Oh they have been in flowering for 4weeks and 1day.

I have read that the red stems are from phosphorus deficiency but it also could just be the strain.

I have read that epsom salts is good to use but I never use anything like that on my plants. I personally would flush them with fresh water and see what colour comes out the bottom of your containers. If it is yellowish then you are doing a nute overkill but wait for suggestions here because I am really not sure.

Buy a bottle of CalMag and use it according to the directions on the bottle. Leaves will green up.

Vi

thanks lacy i think they are northern lights
here is some more info on my grow
they are in soil cheap asda compost + 20% perlite
temp is 82 humidity is 50-55% (65% after watering)
i think the ph is about 6.0-6.5

i watered them last 5 days ago (with same nute but at 3ml per litre )had red stems on one of the others that has since cleared up

i watered them today ( with nute 5ml per litre)then noticed the marks on the leaves just after maybe i should'nt have put nute in this time

they were dry last night left watering till today

before that they had plain water for 2 weeks as they were transfered into bigger pots

thanks viredd i will look into that

anyone else got any ideas or confirm viredd or lacy