Well, I went down and he gave me one for free. We've been friends for over a decade, so he wants to try and help. So I now have a digital reader as well as the swing arm one. So there's that.I would not run out and buy a refractometer or anything else right now. I also use a plastic, swing arm hydrometer and have for 50 years. Is it accurate? Not at all so you have to calibrate it. You do that by bringing it to your LFS and have the person there test their water with their refractometer. Then use your swing arm hydrometer and using a permanent marker, make a line on your hydrometer with the reading on their refractometer. Let them spend the money.
As for your well water, that is questionable and I would not use it unless you put it through an RO.
Well water could be loaded with metals and I feel that may be your problem as your fish do not look sick.
Ph, salinity and temperature will not kill your fish unless they are way off. Only metals will do that.
I also do not think it is ammonia.
Good luck
Alao, I don't use my water because it being well water I won't even drink it, I'd never put my fish in it haha so I go to my buddies house and use his water. Not as good as ro water but better than well and it had a closer PH than what else I found. I have recently learned, that's fine able with salt mixing and the like. So I'm gonna look into an RO system of my own and see if I can get that going which, from the sounds of it, will help in the long run.
So going forward, RO water only.
Thank you for your input.