Water softening questions

[Ronald & Christine Gillis]

I need to probably install a water softener but I have a couple of questions.

My water tested for hardness at 12 Gr/Gal, Iron and manganese well below threshold. I have been getting these grains of tan colored sand in my shower head and faucet screens, they are almost like sand. I believe I may have to replace my hot water coil in my furnace as well. My water taste great.

Now the questions, Are they problems associated with hard water the result of a reaction between heat and hardwater? That is, does it make sense to treat only the hard water that is going to be heated with a softener while while allowing (by way of a tee) cold water to reach the cold water faucets? The reason doing this is to preserve the great tasting water I have while treating the water that is eventually going to be heated.

I hope my thoughts are clear and appreciate any thoughts and comments. Gill

[Gary Slusser]

You're better off softening all the water and running a hard water line to a separate faucet at the kitchen if you insist on hard water there.

As to the purchase, I say the most important component of a softener is the control valve since 95% of problems with a softener are caused by something to do wit hthe control valve. I believe the best control valves on the market today are the Clack WS-1 and Fleck 7000. They both have variable reserve, all parts are DIY replaceable without any special control valve specific tools as all other Fleck valves require. Both also use soft water for brine refill which keeps the salt tank clean. And the 7000 has variable brining which saves on salt. The Clack WS-1 is the easiest control to program and repair while the parts are the lowest priced of all manufacturers. All parts can be replaced in as little as 10 minutes, including the meter turbine without removing the control from the by-pass valve; it's truly a DIYer's dream. Plus the price is right if you buy over the internet, and anyone that has the desire can install their own softener...

[David_T (MO)]

Gary has one opinion (as a softener salesman) and I have another (as a water production utility laboratory employee). We've bumped heads in the past and have agreed to disagree.

Gary has all sorts of numbers ready to show you how much money a softener will save you over time. I don't quite trust those numbers and don't see the need to add yet another device that will have to be maintained and replaced (about as often as a water heater on hard water) further down the road. Much cheaper in my opinion to just replace the water heater when needed (every 10-15 years on hard water... maybe, some people go as long as 25 years without problems).

If you do choose to soften, then I agree that only the hot side should be treated. Again, Gary will have all sorts of number ready to show you how much money you'll save by softening the whole house. Of course his industry is also interested in selling you salt. By softening just the hot side you'll save money on things that don't need softened (Gary would disagree saying everything needs softened) and only dump half the used-up salt down the drain as you would softening the whole house.

Another thing to consider. Removing the calcium from the water by softening does remove scale. Gary would have you believe scale is BAD, however it does provide a physical barrier that actually protects your metallic pipes from the natural corrosive nature of water (think Grand Canyon). This corrosive nature can be further enhanced by adding a recirculating hot water pump to your hot water system. I've seen these softened recirculating hot water system develop pin-hole leaks in as little as five years. Talk about major money to fix!

Here's a little snippet from years past.

[Doug Miller]

Hello.... your reality check just bounced.

Removing calcium from water by ion-exchange softening *prevents* scale from building up, but it does not to any significant degree *remove* scale that already exists.

The Grand Canyon is the result of *erosion*, a completely mechanical process, not corrosion.

And water isn't "naturally corrosive" to begin with.

I don't know what kind of work you do at that water utility laboratory... but I'll bet you're not a chemist. (For the record, I'm not either, but I *did* have two years of college chemistry which I haven't managed to entirely forget.)

[David_T (MO)]

SMSU BS degree with a Biology major, Chemistry minor, went back and completed all the requisites for a chemistry major, went back again and got a second Computer Science major with a Math minor. 20 years in the water production industry. I'm now Senior Analyst in our Lab.

I'll have to respectfully disagree with your statement on calcium.

Since this is not a technical forum I tried to put my explanation in non-technical terms. Corrosion within household plumbing can be from physical as well as chemical causes. A small amount of scale build-up on the inside of metallic pipe can protect the pipe material from both forms of corrosion. Removing that protection by softening and you expose your pipes to potentially corrosive water. If you wish a technical explaination of the chemistry of that removal...

CaCO3 (solid) Ca++ + (CO3)-- (Hard to write stoichiometeric equations in ASCII.)

Reduce the concentration of one component from one side of the equation (say Ca by softening) and the water chemistry will force a balance by dissolving solid CaCO3 (scale) until a new stoichiometeric equilibrium is reached. Continue to soften and all the scale within the pipe (and water heater) will be dissolved over a relative short period of time (depending on how thick the build was to begin with). This process also works in the reveres and explains how cave formations are made. CO2 for the air dissolves into the highly mineralized water getting ready to drip from a cave ceiling (which begs the question how does it get highly mineralized if scale can't dissolve back into water), dissociates H20 to form a mild carbonic acid. The carbonate concentration increases on the right side of the equations (forcing the balance towards the solid), combines with Ca ions to precipitate CaCO3 (limestone and scale are pretty much the same thing you see) which creates those beautiful formation found in limestone caves throughout the world.

Water is the ultimate universal solvent (if it weren't, life would not have evolved on this plant). That means almost everything will dissolve in it to some extent (even glass). Water in its purest form, when exposed to air, will have a pH around 5.5 Units. That's fairly acidic as such things go and therefore naturally corrosive in my book. As water passes over natural stone it will dissolve minerals from the stone (this also qualifies as being corrosive to the stone). These dissolved minerals can help buffer water's natural corrosive nature so that when a particular compound reaches equilibrium between the dissolved ions and the solid (using the stoichiometeric equation as an example for CaCO3) no more solid will dissolve, i.e. the water is non-corrosive to that solid. Disrupt the equilibrium (by removing Ca via ion exchange softening) and the water is once again corrosive to that solid, in this case, scale. Sorry for the lengthy chemistry refresher. ;-)

[willshak]

On 12/8/2004 4:43 PM US(ET), David_T (MO) took fingers to keys, and typed the following:

Yeah, but, why is the ocean blue?

[Charles Spitzer]

same reason the sky is blue

[David_T (MO)]

And that's why the oceans are gray when the sky is gray. ;-)