Mag def please help identify...

Hello I previously posted pics of my cuttings 2weeks old and they had what I thought to be cal or mag def..


now as there getting close to the end second week the leaves are curling upwards/inward(like a venus flytrap.) Im planning on treating by adding 1 tsp epsom salt to 5 liters of nutriented water...would this be sufficent and is the regular "Bath" epsom salt from boots phamacy okay to use?
P.S sorry bout the pics...

Okay so there must be a reason as to why my first two posts have had over 100 veiws in total and no replys so ill start by adding some more infomation...

Potted from cuttings(kush) into canna pro+ (11th/Aug)
Placed Under a 600w Hps with 8" outtake and a 5" intake and 2 passive(temps fluctuating from 27 to 34).Humidity 40-50%
Fed Canna coco nutrient at half strength for the first week,now feeding full strength(following canna grow guide).
I'm getting readings of 0.8,1.0 on EC meter and getting PH to 5.8 smack on when mixing nutes.

If theres anything else ive missed that might help then just ask...even if its just so I know there is somone acknoleging my existance.

I had a plant that started looking like that. Found out it didnt like much ferts. Are you feeding every watering? I would try to just water her and see what she does.

Yeah been feeding every water...guess ill just give PHed water next..when you did relise,did you come up with some kind of schedual like 2 feeds 1 PHed water or somthing also do you think it is worth adding a little epsom salt(half a tsp per 5 liters) just to be sure. I suppose its best to do one change at a time to single out the problem...allthough there is also a purpleish discouleration to the stems.

Thanks very much for the reply btw (y)

After hours and of searching ive found a pic that will help diagnose my problem...it is posted on RIU in the diagnosis section but for some reason I cant see it...
View attachment 2312688
The leaves are curling upwards due to a lack of magnesium(or a abundance of potassium).Also ive just found this information aswell..."Coco is not the same as soil. You need to use nutrients EVERY TIME!!!!!! When you water you need to think about watering the coco rather than the plant. The Coco stores the nutrients until the plant needs to use them. If you water with just water you wash out all of the beneficial bacteria, trichoderma etc and have to add it back in to get the performance out of your coco."

So basically Im just gonna keep feeding as normal and add 1 tablespoon of epsom salt to 1gal/5 liters of nuted water and also put a small quantity in my foliar spray(just phed water).Due to the lack of comments and help ive had its taken me absolutley ages to find this helpful information...Being a newby I thought I would recieve more help from the RIU community but obviously the weed DR's are on holiday...guess ill come back when there off vacation...