Through the process of best home water softener filtering, suspended particles, parasites, and bacteria are removed or reduced in concentration. Filtering the water may not be a good option for you, depending on your situation. Many under-sink filtration systems can clean water for more than four people and can get rid of pesticides, heavy metals, and volatile organic compounds. Beyond only filtering your family's drinking water, there are numerous other considerations. A semipermeable membrane is used for water filtration during the reverse osmosis process.