I meant to tell you Epsom salt is not salt/sodium. it is safe to use, so no need to go light on it.
Gypsum has to be mixed in the soil so I assume it is slower acting?
Epsom salts have many benefits for the body since they help draw toxins, sedate the nervous system and soothe and soften feet. Besides being beneficial for your health and beauty, Epsom salts are also beneficial in your garden. Epsom salts, or magnesium sulfate, help make plants bushier, help produce more flowers, increase the production of chlorophyll and help seeds to germinate. Used as a fertilizer, Epsom salts help absorb phosphorous and nitrogen. Epsom salt is also a source of calcium, and will help restore the calcium in your plants and soil.