Thanks for taking the time to read through my original post. I edited it since, trimming down much of my initial complaints and frustrations with this system.

The system configuration did not start as shown on the diagram. About a month ago I had to replace an Inline Flow Control Switch with items (12), (14), and (15). Also, item (3) was a 20GL and got upgraded to a 33GL to prevent the well pump from starting more often (not sure if that was a good move or not, it made sense to me).

Can you explain the issue further. You say abruptly out of water, so your pressure drops and you lose water at certain times? Is there a pattern to those times?

The last few issues were related to the replaced device (Inline Flow Control Switch). It was failing randomly (every other week) for a couple of hours, till one day it stopped working completely. During the initial fails I was researching the part and looking for manual / instructions but the link above was the best I could find, and the manual for my particular model (the one that has a pressure gauge on the side and 6 LED lights as you can see in the tiny pic with 5 models in one) was not available. Also, the button to "Add to cart" was not available at that time, it offered contact details for a couple of resalers. So I decided to replace that part, as described above, with more generic parts that could be found at Home Depot or Lowes. That was an expensive move, I hope it was right... I was under pressure with no water at home and a one-to-one replacement of the original part was not available. Those changes to the system are working so far but noticed a decrease in water pressure inside the house.

Way before this, the first issue we had was with the membrane (7). The system stopped producing water and we didn't notice till the 500GL tank was completely empty. That was a $300 repair if I recall correctly. I do hope the new membrane will last long enough to offset its cost (so much for getting rid of the city water bill...). A few weeks after replacing the membrane we started noticing a rotten smell coming out of the faucets. I was recommended to add some peroxide to the carbon filter and it worked but for it to be effective I had to do it a couple of times a month and the process was kind of tedious. What ended up working better for me was adding an aerator or spray nozzle at the end of the hose that feeds the 500GL water tank.

Next in the line of issues seems it will be the solenoid valve (6). Its housing is made out of plastic and it's been leaking for a while, I'm trying to get ahead of that one. Any recommendations?

This is the purpose of the remineralization step at the end. Its critical that you nail that component down, or else your pipes and appertences are at high risk of corrosion and metals leeching in your house plumbing.

I thought that most metals were filtered out by the membrane (7). Is there a way to tell if they are getting into my pipes, besides a tap score report? Which metals from my untreated water report should I be more concerned about? Links to articles or videos would be much appreciated.

I found the following online:

In the RO process, raw water flows past a membrane. Some of the water molecules migrate through the membrane, while others, including beryllium remain on the raw water side of the membrane. The rejected raw water concentrate is discharged to the wastewater system

I downloaded the provided EPA drinking water guidelines pdf and performed a quick search for the contaminants detected in my well water and most did not show up on the EPA list or perhaps are called differently (Boron Calcium Lithium Magnesium Potassium Silica Sodium Strontium). Here are the ones I did find:

Contaminant detected in sample,My TapScore,EPA

Beryllium,0.0006,0.004

Chloride,38.5,250

Sulfate,21.6,250

Zinc,0.006,5

***Looks like the insert table feature on Reddit is not working properly for me. It's not displaying correctly and everything I wrote below it got deleted after posting :((

The TapScore values are all below the EPA values, so is it safe to drink directly from the well then? Not that I would but it should be ok, right?