There are some great resources on the keto subreddit (reddit.com/r/keto). I personally had similar issues when I first started keto - several times a week i found i had to be conscious of my electrolyte intake and would supplement with broth and often almond milk (potassium). However 6 months in I've found it's less of an issue, even at lower electrolyte intake, but I'm not sure why. I never found the need to hit the super high recommendations on /r/keto though - I found that 4,000 - 5,000 mg per day was more than enough, and I'd get heart palpitations and muscle cramps generally under 2,500 / day. You'll see a lot of people on /r/keto saying you _have_ to hit 7k+ a day, and people who drink salted water all day - personally, I think that's overkill.
I take ZMA and potassium daily. I will drink electrolyte water too. When I get home from the gym and feel drained I will drink 8oz of chicken broth for the salt. I had some severe cramps before starting this.
I don't know what the daily values are to be honest. I just take it until my symptoms, mostly cramping, go away and stick with that dosage. I basically eat broccoli or brussels sprouts with dinner every day. They both seem to have a decent amount of potassium.
I buy potassium bicarbonate from Amazon in bulk -- ten bucks a pound. Winemakers use it to reduce acidity in their product, but it's easy enough to mix half a tsp in water twice a day. Lot of research on bicarb, too, so useful outside of keto issues.
