A glass of water containing that low an amount of sodium qualifies for the US Food & Drug Administration’s “very low sodium” category.

Why do water softeners contain salt and/or sodium?

The majority of water softeners utilize a resin bed, which you can see at their website, comprised of negatively charged plastic beads packed with positively charged sodium ions. As source water passes through the bed of beads, calcium and magnesium ions with stronger positive charges disrupt the sodium ions’ bonds with the beads and form their own bonds with the plastic beads.

Eventually after a water softener operates for a while the supply of sodium ions in the resin bed gets depleted and when that happens the resin bed must get recharged using a concentrated salt brine solution that more or less overpowers the collected calcium and magnesium and causes them to become dislodged from the plastic beads. Sodium molecules then take their place on the resin beads and the magnesium, calcium and excess sodium molecules get flushed out of the system.

After a properly completed flushing and rinsing, a water softener operating properly ought not produce water that has a salty taste since all of the actual salt (NaCl) should have gone out as waste water during back washing.

Measuring water hardness

Scientists typically measure water hardness using one of two scales: Grains per Gallon (GPG) and Parts per Million (ppm). One grain per gallon of hardness equals approximately 17.1 ppm of hardness.

You may also see ppm expressed as milligrams per liter (mg/L) in some literature.

Rating categories for water hardness

As a general rule,

• Water that contains less than 1 GPG or 17.1 ppm hardness gets labeled as ‘soft’.
   
• Water that contains between 1 and 3.5 GPG, or 17.1 to 60 ppm, hardness gets labeled as ‘slightly hard’.
   
• Water that contains between 3.5 and 7 GPG, or 60 to 120 ppm, hardness gets labeled as ‘moderately hard’.
   
• Water that contains between 7 and 10.5 GPG, or 120 to 180 ppm, hardness gets labeled as ‘hard’.
   
• Water that contains between greater than 10.5 GPG, or 180 ppm, hardness gets labeled as ‘very hard’.
   

My wife and I just bought a home and although the real estate agent showed us all sorts of confusing paperwork that supposedly proved our tap water passed all sorts of tests we still have our doubts. We want to do some testing ourselves. What are the most commonly tested water parameters? Thank you.

We will answer that question in two ways: 1) We will ask a water testing and filtration dealership; 2) We will look at this site’s history and see what pages people have loaded most often this month.

IsoPure Water replied to our inquiry by listing the top three selling water test strips: SenSafe Free Chlorine, WaterWorks Total Hardness and SenSafe Total Chlorine.

With regard to the most popular postings on Water Testing Blog, in the month of January 2010 more people looked at these blog entries than any others:

• Hardness: Grains per Gallon vs. Parts per Million
• Testing Chlorine Levels: Drinking Water vs. Pool Water
• Your Baby Needs Safe, Clean Drinking Water
• Free Chlorine, Combined Chlorine and Total Chlorine
• Acceptable TDS Meter Readings Do Not Guarantee Safe Drinking Water

“Overview: This standard covers residential cation exchange water softeners designed to reduce hardness from public or private water supplies. Additionally, this standard can verify the system’s ability to reduce radium and barium.” (source)

Cation-Exchange Softener:

• Typically used to soften hard water (water containing excessive amounts of calcium and/or magnesium) by ‘trading’ minerals with a strong positive charge for those with a weaker positive charge.
• Often referred to as ‘water softeners’.
• You will find most systems of these water hardness treatment systems functioning as whole-house water filtration systems.
• These systems effectively remove calcium and magnesium (water hardness) which can build up and leave depositis in plumbing and faucet fixtures over time. Water softeners can also remove contaminants such as barium which can cause health problems in humans.