Regardless of whether you have city water or well water, the only way to avoid spotting and mineral build up is to wipe them dry with a towel or squeegee after use.

Use a ph neutral cleaner. I'll guarantee you that same tile store will be able to get you one from one of the sealer companies.

update - did all the checks from Bosch instructions and checked filters on all fixtures in the house. The two fixtures that had most dirty filter were kitchen sink and guest bath sink. The inlet water filter in the heater was a MESS - lots of clay dirt, tiny pieces of grass, and its physical condition is not good so it has to be replaced. We took it out and continue to use the heater as normal until we get replacement. It costs $7, and $7 shipping, so I am going to buy two - for the same cost of shipment - to make it worth the cost. Now that we have big filter in main line , this little one should not have too much work to do. I also changed a rubber washer in our showerhead to open water flow. I know these reducers are designed for city people to reduce their water bill, and we had it in the city, but now we dont need it. All this really opened up water flow and reduced problem but not completely. Right now temp setting is at 104, but the outlet hot water pipe temp reads at 115F. We should still do the multimeter check of the water temp sensors. But I was able to enjoy shower for the first time in longest time. Definately a noticeable improvement so thank you all! also, our PRV does not have a tap to check the pressure, so we will install a gauge in the line, and while we are at it - we will re-arrange the order of filter and PRV.

If you are actually referring to 7 gpm makeup flowing into your well, that is decidedly NOT slow water production. There are many wells operating successfully across the US with 0.25 gpm makeup. If your well is so shallow that is has essentially no water capacity, however, that would be a problem. You have several major issues to deal with: Sediment. Unfortunately, continual high sediment indicates a problem with the well - too shallow, insufficient capacity, poor location, etc. It can be dealt with, but I would still be talking to a well driller about options. Generally sediment filtration should be the first step in water treatment. Iron. At present we don't know if your iron is ferric (particulate) or ferrous (dissolved). If it is ferric, it can be removed by sediment filtration. If ferrous, another method will be required. Hardness. At about 10 gpg (grains per gallon) your hardness is certainly high enough to cause buildup in your water heater and in your shower heads, particularly in combination with the sediment in your water. Few people in the home, combined with high-flow fixtures. This makes equipment sizing more complicated. When you have iron in your water, it is very difficult to eliminate IRB once they have established themselves in a well. If you have chlorine residual and tests still indicate IRB it could be cross-contamination during sampling or inadequate chlorination of the well. Even if you do eliminate the IRB, you will still see staining from the residual iron in your water - it takes very little to cause visible rusty stains on fixtures. There are lots of options for iron removal - I'll provide a brief list in a separate post. You really ought to get a local pro on site. With your water conditions, the ability to turn over water treatment to an on-site expert will be very helpful. Have you spoken to your neighbors about their water? Do they have the same issues? They may be able to suggest a good local pro.