I have a hotel that uses groundwater, but the water quality is not good. What can be installed to improve water quality?

It depends on what kind of impurities are and what kind is not good.

If it's only turbid and has sediment impurities, it's easy. Just install a two-stage sand filter between the water tower and the water pump. A few thousand dollars of sand filter tanks, a hotel is enough. Backflushing every day to ensure the filtering effect.

If bacteria or heavy metals exceed the standard, this is useless and another device is needed. Bacteria exceeding the standard need chlorine dioxide sterilization device. If the degree is not high, you can also consider ultraviolet germicidal lamp.

If heavy metals and pesticides exceed the standard, you will give up your idea. Forget it. It's not incurable, but it's more expensive than buying tap water.