I have written series of posts on various aspects of Water Softeners from Why do I need water softener, What softener size is good for my home, What softener to buy, water softener vs reverse osmosis and how to interpret TDS readings etc. However, some of you have reached out to me asking about my opinion regarding some popular brands.
This is a great question in general and leads to the discussion about salt based vs salt less water softeners including electronic conditioners / de-scalers. As mentioned in some of my posts, I will try to stay off from brands while trying to address this question. Essentially salt based water softeners remove hardness (calcium, magnesium and iron) physically from water via ionization process i.e. by physically removing one calcium molecule for every two molecules of sodium (salt) and putting removed particles (calcium, magnesium and ferrous) into drain and ensuring only softened (water without calcium, magnesium and ferrous) water is supplied to the house from that point onwards.
Salt based softener's require the softener's drain be connected to the proper drain in the house per the city code (most cities including Pleasanton, Dublin and San Ramon require this). Excellent NSF &/ WQA certified salt based softeners typically range between $600 - $1100 in open market. Most come with 5/10 year warranty for resin & brine tanks and with very good warranties for the control valves. Most of them being open systems, parts are easy to find and systems are easy to maintain. On the other hand, salt less water softeners condition water with what is called as "Template Assisted Crystallization" (TAC). Different salt less vendors may call this technology with different marketing names. However, at the core of the TAC (template assisted crystallization) is polymer beads that hold (calcium) microscopic nucleation sites to form crystals and once formed, detach and do not bond to anything. Thus ensuring the calcium (hardness) not settling down at the bottom of the plumbing lines and thereby appearing to provide the benefits similar to salt based softener.
However, calcium, magnesium molecules are still present in the water as they are not physically removed. This is the reason some people despite of using very expensive salt less softeners (technically conditioners) complain seeing white powder (calcium) rings around faucets including stains when they wash dishes etc. These are very expensive systems and generally range between $2k - $6K but do not require drain as they do not remove anything. One more thing is the mix is electronic de-scalers / conditioners, you can search costco.com or several online sites and you will find several electronic de-scalers / conditioners in the range of $150 - $500 providing benefits similar to that of salt less systems but using electro magnetic waves. Technically electro magnetic waves do not let calcium settle in the plumbing lines as they diffuse or agitate the settled particles and make them float in the water.
In fact, this is the only technology that claims to be able to remove even existing scales in plumbing lines with over a period of time. This technology doesn't involve any maintenance costs. Once installed it does it's thing for the rest of the life without ever requiring to do anything. Only exception being if unit gives up ( unlikely but being an electric device you never know), then you need to replace with a new one. You can do lot of reading about this technology online. All of them are great technologies and have their own place and market. I personally would go with a salt based softener unless installing a dedicated drain (in some cases where drain is not accessible near by) becomes very expensive.
At core of this topic is, getting rid of hardness from water and removal provides benefits to appliances down stream and also provides other benefits such as softened skin, hair, dishes without stains and clothes not getting turned into brown during wash cycles etc. If that goal remains the same, salt based is the best technology that removes hardness. From a price perspective, with standard install costs including softener, salt based softeners costs around $1500 - $1800 to setup and on average cost about $50/year for salt and about $50 for water (that gets wasted in drain).
Whereas salt less setup could cost anywhere between $2.5K - $7K and normally most vendors would like you to sign you up for their Annual maintenance contract for around $200-$300/year. Most salt less systems are by closed vendors (meaning you have to only rely on that company for any parts, repair, service etc.). Both Electronic de-scalers and salt less softener's make similar claims ( using different technologies) in terms of the water conditioning &/ softening and are certainly more eco friendly vs salt based softeners.
Given the average life of water softeners is around 10-15 years and based on what each of these technologies actually do, you decided which one is best for you. I have seen people installing only electronic de-scaler, only softener and some installing both salt based softener & electronic de-scaler and some salt less softener & electronic de-scaler. At the end, either you should be able to make up your own mind on what is best for you or seek advise about best technology / combination for your specific needs and desired outcomes. Cheers.