Potassium is nothing to be afraid of. U logged my food for some time and calculated various nutrient intake and I was on average getting around 2000mg a day. The FDA RDA is 4700mg.
At the time by blood work showed potassium of 4.2. Now I have been supplementing potassium at approx 2100mg a day for a year and guess what? My serum potassium level is still 4.2.
Just be smart about it and you shouldnt have any problems.