Can you quantify the benefits of the electrolyte mix? My hypoperfusion (which doesn't appear to be heart related and I pass the tilt test) is what keeps me bedbound 22 hrs out of 24.
People with PoTS often take electrolyte drinks to increase their blood volume. Advice varies. There have been times when I have made versions of WHO oral rehydration solution discussed here
https://forums.phoenixrising.me/threads/desperate-need-of-help.60803/#post-989561
In the short term these things can be pretty effective but I did not feel good on the glucose or amino acid based mixes. So I went instead for solutions of water or tea and salt and potassium chloride which is less effective at dealing with PoTS but did so without negative side effects.
Re bicarb, I noticed it in an electrolyte mix recommended on a medical site for keto diets for childhood epilepsy that I cannot find at the moment. So I started adding some and adjusted the salt to bicarb to potassium ratios over time.
I added the calcium and magnesium because I found that I desired a mineral water that was high in them but could not live with shear volume of plastic waste I generated when I bought some.
re hypoperfusion. I don't know if you have looked at this but every so often someone brings up Les Simpson's work on red blood cell deformability in ME/CFS.
http://www.positivehealth.com/artic...-of-blood-flow-and-evening-primrose-oil-in-me
Before PKD I tried taking about Evening Primrose Oil. At the time I was suffering from senses of air hunger (which felt to me like asthma without the wheezing) and a sort of cold tingling/ not-quite pins-and-needles sensation which was mostly in my arms and legs. I found that it was made worse by bioflavanoids and hibiscus tea (which I was taking to promote bile flow) and stopped when I was taking the EPO.
When I switched to the PKD I stopped the EPO. I have not had a return of the sensation of air hunger, which is the worst, so I have been happy to stop it. But I guess it might be worth testing again when I reach a new equilibrium.