Epsom salts in DWC?

I have a magnesium deficiency and was wondering if people have used epsom salts in their DWC? If so how much for say 14 litres? Think thats bout 3 gallons...

3.7 gallons , figured the extra .7 might make a difference.

I use 1 tsp per 5 gallons

jIMMYJAM22: I'm not trying to be a smart ass, but if you have a nutrient deficiency, what nutes are you using? HSA

Its a brand called "Growth Technology" and the stuffs called optimum bloom. Im from Australia btw. Heres pics of the plants: https://www.rollitup.org/dwc-bubbleponics/458283-4th-week-flowering-pics-plus.html

GT Nutes are generally good, ive used formulex, thats supposed to be for babies all the way through and cropped more than 0.65 grams per watt. they are one part, buffered and more sophisticated products than the 2 part types

Are you Aussie?