Re: Sorry Shelleycat one more question...
blood tests are inconclusive for potassium because potassium is within cells and in between cells. The serum (blood) level of potassium can tell you about kidney function but that's about it. Low levels tho is not great, and that's weird because with a malfunctioning kidney they should be running high, so if I were you I'd assume that I was low in potassium and drink the cleansing drink.
Doctors know next to nothing about kidneys because no one famous has had kidney disease so there's no money for research. The only orthodox medical cure I ever found for kidneys isn't even practiced anymore, it was done back in the early 1900's at the Mayo Clinic before they started pushing pills. Basically their patients drank nothing but raw, organic milk, and lots of it. They did a lot of sweat therapy and daily enemas. Lots of people with renal failure and edema made good recoveries.
It rather depends on where the cyst is on the kidney and whether it's causing proteinurea/foamy urine whether you can take a lot of herbs and herbal teas. You may want to at the very least take things that help the kidneys cleanse, but if your urine test came back fine then maybe the cyst is benign and localized. In that case, making your body more alkaline is the best thing to do. Most cysts are due to toxic acidosis.