I have some friends that recently purchased a home in the pacific northwest. Apparently there is a lot of iron in the water and they're looking for a whole home water filtration system to protect their pipes.
Please provide recommendations and an explanation of why you recommend this product versus other products.
I recomend you start here: http://blog.sls-construction.com/2012/going-off-grid-water-filtration
Just like many other aspects of our field - it is better to test & not guess - then go from there
My recommendation is to read about it and talk to all the suppliers in your area until you get a thorough idea of what you need. In my case our well water has iron and clay sediment in it and it's acidic and slightly hard. We have always filtered our water with a couple of whole house units -- to help my laundry not be ruined but when the showers and sinks started getting green stains on them, my research (on the internet) started! I found that there are a couple of kinds of iron (my water has the visible kind -- making the water cloudy from the tap) and that the green stains were from acidic water reacting to my copper supply lines. I also found that you can soften water with potassium instead of salt but I wasn't sure I needed a softener after research. My goal was to buy equipment outright not rent monthly -- If you have the money this is the way to go (you still have to maintain the system but it pays for itself in just a few years) The second thing I did was talk to friends who had water issues. From that I found out that some people paid A LOT and didn't totally have their problem solved. The third thing I did was go to our area annual builders' show on a mission. That year I talked to everybody there in the water treatment biz. A lot will test water for free and I asked two of them to do that. In the end I found a local guy who had been in business for years who builds his own systems from purchased components. Our system has a "Big Boy" whole house particle filter 1st in line. It takes the sediment and iron out with a filter the size of a roll of paper towels (which is changed about once every 3 months instead of monthly like our previous smaller ones). Then the water passes through a neutralizer which takes the acid out (this process uses minerals so that makes my borderline hard water too hard). The last step in my water treatment system is a softener. I found (in my reading) that I could use potassium instead of salt (extra salt in the water can be bad for people who are prone to high blood pressure & other illnesses). Potassium comes in the same kind of bags but is about 2x the price at around $20/ bag locally (Central PA). Our system cost us about $2,200 three yrs. ago. Of the other companies I talked to, no one told us we needed a neutralizer and a softener yet the 2 major national brands' cost was at least twice the price. One of them was more like $5500 as I recall.
PEX "pipes" do not need any protection from iron and copper is mostly immune as well. . It is the fixtures and appliances that will suffer staining.
A local water quality company is the best resource for this information. Filtration is the blocking of particles. You may need filtration but your inference is to chemistry i.e. water conditioning.
Excellent advice on the testing -- you can't treat what you don't know about.
A softener will remove small amounts of iron, but the media will eventually become iron loaded if you ignore it. A cup or two of anhydrous citric acid added to the salt tank every so often will usually mitigate that along with a properly engineered softener bed (using a turbulator instead of a spreader at the bottom.) This worked quite well for us with a well that had 0.47 PPM of iron and was staining pretty much everything. Higher levels of iron will require more intensive treatment using specialized media (manganese greensand is a common one.)
I was in the business of cleaning up water at one point. We produced spot free pressure washers for car dealers and marketed them nationally.
Much of the PNW had pretty clean water. I would use how many galllons a DI or Deionized point of use would exhaust to make this assessment. I rarely was concerned about what I was filtering simply how much and what was cost effective for my customers
We also sold commercial RO units 1000 gallon per day and up for dealer that used allot of water.
Our strategy for iron on an RO was a sand pre filter. We used this before the activated carbon which then ran directly to the RO. This needed to be back flushed once a month. In our local market I was always surprised at how much "rust" came out during a back flush. While effective hardly recommendable for someone bathing or drinking it
There are "whole house filters" that have a KDF media and do a good job of automating and back flushing automatically. These are often sold as "saltless softeners which they are not. No ion exchange takes place. Some of these have magnets. You will here terms like realigning water and making water wetter which is all sales junk. They do however trap iron and back flush it and remove chlorine as well as other contaminants
For real soft water one must have an ion exchange such as salt or potassium pellets that rinse down and need to be replenished.
Many of today's pleated filters do an excellent job of trapping microns including iron. A two stage filter with a pleated filter and a carbon block will take much out of municipal water for a low cost. The filters should be changed either monthly or bi monthly. If a customer cannot commit to this then the whole house with KDF are a good option
There used to be a great site by a Canadian Water Scientist called waterdotcon.com site that explained all sorts of products. What worked and what did not and why. Sadly it went away.
Many water profiles can be found on home brew sites. Brewers want to know what is in the water.
If its well water all bets are off and it should be tested.