Some General Softener Questions

[Treeman]

The Autotrol "suggested salt settings" table shows that 9 lbs. salt in a 1.5 cu. ft. softener = 30K grains capacity.
9 lbs. salt in a 2.0 cu. ft. softener yields 35K grains capacity.

1.) If you are using the same 9 lbs. of salt, why the capacity difference? What am I missing here (go ahead, make me feel stupid). It seems that a given amount of salt should displace the same amount of ions regardless of the resin bed size.

2.) Please explain the pros/cons and preferred recommendation to have the brine tank fill pre regeneration or post regeneration. My unit will probably have a time over ride of 7 days.

3.) The Clack valve on my new softener is model WS1 CH. What does the CH designate?

Thank you.

 

[Reach4]

1. This graph is pretty good at showing this frequent topic: http://www.watertreatmentguide.com/brining_curve.jpg

2. Pre-brining is important when using KCl rather than NaCL because the solubility of KCl varies with temperature a lot. Post brining leaves water in the brine line rather than brine between regens. That is probably not significant. If doing variable brining, prefill is manditory. That varies the brine based on how much capacity remains. I may well have missed some advantage to post fill.

Why have the 7-day override? If you don't have iron, you would usually want to set that higher on a demand-driven softener. That way, if you are away for a while, the softener does not needlessly regenerate.

3. I have seen CL, EI, TC , but I don't know what CH is. Do you have a metering assembly with a cable to the controller? Does your controller report gallons remaining/used to you as you use water?

 

[Sponsor]

 

[Bannerman]

Salt efficiency will vary depending on the amount of capacity to be regenerated compared to the total capacity of the resin. The quantity of resin will not only determine the total and usable softening capacity but also the flow rate supported before hardness will leak through the softener.

You would not want to use the total resin capacity since after a point, the remaining softening capacity will be too low to support softening at your usual water flow. Hardness leak through will continue to rise as more capacity is consumed.

Regenerating capacity and salt efficiency can be easily understood when compared with 1 cuft resin.

1 cuft regular resin = 32,000 grains total capacity when the resin is first manufactured. To regenerate all 32K grains would require 18 lbs salt which equals 1,778 grains per lb of salt.

As some resin beads will wear over time and some will be broken in manufacturing and handling, the worn and broken pieces will be flushed to drain during regeneration and so some capacity will be lost. In anticipation of these losses, resin is often considered to have no more than 30K capacity/cuft. To regenerate that 30K would require 15 lbs salt which equals 2K grains/lb salt efficiency.

Using the same 1 cuft resin but using a lower salt dose would result in the following regenerated capacity and salt efficiency.

10 lbs salt - 27K grains usable capacity - 2,700 grains/lb efficiency
8 lbs salt - 24K usable capacity - 3K gr/lb efficiency
6 lbs salt - 20K usable capacity - 3,333 gr/lb efficiency

The 1 cuft examples can be multiplied by the applicable quantity of resin in your specific softener.
For instance, for a 1.5 (48K grain total) softener:
6 lbs/cu ft = 9 lbs salt - 30K grains usable capacity - 3,333 gr/lb
8 lbs/cuft = 12 lbs salt - 36K grains usable capacity - 3,000 gr/lb

Although salt efficiency can further increase with lower salt dosages, water quality can suffer so it is generally recommended not to go below 6 lbs/cuft.

The two softener sizes you mention, although using the same total amount of salt, are drastically different in terms of pounds per cubic foot of resin. A 1.5 cuft system using 9 lbs = 6 lbs/cuft whereas a 2 cuft system regenerating with 9 lbs = 4.5 lbs/cuft.

 

[Treeman]

Thanks, guys. But, I am still dazed and confused.

@Reach4 - I DO have a little bit of iron, thus the over ride as recommended everywhere. I didn't want to face the wrath of Dittohead ......in jest, of course.

Brine fill pre recharge vs. after recharge? One person here suggested the tank remains cleaner if it fills just prior to recharging (manual says it happens 2 hours prior to recharge). What is the most common way?

Regarding WS1 CH model: It's definitely not the CS version (no "P" steps). I'm starting to think it might be a proprietary designation for certain "manufacturers"? Or, it is a very old unit found in the local warehouse?

I understand the general efficiency/capacity ideas. Still not sure why 9 lbs actual salt produces more grain capacity in a 1.5 unit vs. 2.0 unit (30k vs 35K in my original table)? It seems that the 9 lbs. worth of salt ions would result in the same grain capacity, concentrated more in the 1.5 unit and spread out more on the 2.o unit.

Per Bannerman: "The two softener sizes you mention, although using the same total amount of salt, are drastically different in terms of pounds per cubic foot of resin. A 1.5 cuft system using 9 lbs = 6 lbs/cuft whereas a 2 cuft system regenerating with 9 lbs = 4.5 lbs/cuft."

The 2.o unit is producing 35K grains at 4.5lb/cu ft. vs the 1.5 unit producing 0nly 30K at 6lb/cu. ft. The bigger softener can utilize that same 9 lbs. of salt better.....WHY?

 

[Reach4]

The 2.o unit is producing 35K grains at 4.5lb/cu ft. vs the 1.5 unit producing 0nly 30K at 6lb/cu. ft. The bigger softener can utilize that same 9 lbs. of salt better.....WHY?

I was trying to think of an analogy, but I don't have a good one. Here is one that may have a little merit. Imagine dirt on a driveway. Lets suppose there is 1 pound of misc dirt spread on the driveway for each 100 square ft. How much water would it take to wash off 50% of the dirt? If you used twice as much water, would you then wash off 100%? No. Probably not even 90%.

If my plan was to harvest dirt, would I be better off with a given amount of water applied to 100 square feet of driveway or 200 square feet of driveway. OK... let's hear your analogy...

See the equation and the concept of equilibrium between sodium and calcium ions shown in this link.
http://www.rsc.org/learn-chemistry/resources/chemistry-in-your-cupboard/finish/4
The first amount of calcium is going to swap with calcium more readily. But it is going to take more sodium ion concentrations to get the last calcium ions out.

I am not saying that I can work the chemistry math and get a result. But the deal seems to me that the first ions will substitute more readily than when the concentration of calcium ions becomes less.

There is a lot of documentation as to what happens at different brining levels. I think you are looking for a model that goes along with that. It is not like trying to neutralize a strong acid with a strong base where everything runs to completion. But this ion exchange goes both ways.

 

[Bannerman]

The 2.o unit is producing 35K grains at 4.5lb/cu ft. vs the 1.5 unit producing 0nly 30K at 6lb/cu. ft. The bigger softener can utilize that same 9 lbs. of salt better.....WHY?

As explained, it's about efficiency. Although not recommended as specified previously, 4.5 lbs/cuft is even more efficient than 6 lbs/cuft which is more efficient that 8 lbs/cuft which is more efficient than ...

If 30K of capacity is required, a 1 cuft softener could deliver that capacity but 15 lbs of salt would be required and excessive hardness leakage would occur as regeneration approaches. A 1.5 cuft unit would provide 30K capacity while using only 9 lbs salt and allowing little or no hardness leakage depending on the flow rate needed.

Although 4.5 lbs/cuft is specified, that setting is not generally recommended, even without iron. As 6 lbs/cuft is the usual lowest recommended salt dose, a 2 cuft unit would then provide 40K usable capacity using 12 lbs salt.

As your softener will be exposed to iron, the most efficient settings cannot be utilized as additional salt and regeneration frequency will be needed to assist in cleaning iron deposits from the resin.

The most common brine fill setting with sodium chloride (salt) is 'post' regeneration. If potassium chloride is used, then the pre-fill setting is appropriate as potassium's dissolve factor varies as the water temperature changes as would typically occur when sitting over multiple days.

With post fill, as salt needs time to dissolve, brine is produced in advance to the next regeneration cycle and so regeneration can proceed without further delay once initiated. Having brine fill at the beginning of the regen cycle, means the regen cycle will be further delayed 2 hrs from occurring to allow salt/potassium to dissolve. As regeneration typically commences at 2am, the delay could impact anyone rising early as the cycle may not yet be finished.

As the brine tank is covered, the only debris that should enter, will be during salt fill and from impurities in the salt itself.

 

[Treeman]

I get it. That lower lb./cu. ft. IS more salt efficient. But, depending on the water characteristics, there is a point where the lower setting is less effective, if that makes sense. Doh! And, it is also a balance of salt AND water efficiency.

The post regen fill also makes sense. Its ready to go immediately.

Life was easier when I didn't pursue the "why and how" of my needs.

Thank you very much.

 

[Reach4]

Having brine fill at the beginning of the regen cycle, means the regen cycle will be further delayed 2 hrs from occurring to allow salt/potassium to dissolve. As regeneration typically commences at 2am, the delay could impact anyone rising early as the cycle may not yet be finished.

The softener is not bypassed during brine fill. Having the fill start at midnight with backwash at 2 AM has the same effect from that point of view as having the backwash start at 2 AM and the fill starting at 3:30. So I think it must be another factor that makes fill last more common.

 

[ditttohead]

Brine fill first creates some unique challenges... covered in my training seminars of course.. The only real problem is in higher use applications the time between refill (typically recommended at 2 hours, more time in cold weather, less time is ok in warm areas) and the regen time is left out of the reserve calculation so... a twin alternating system with a brine fill first would be a little more difficult to do but not that big of a deal except in systems that are severely undersized. Brine fill first is the only option on many systems that don't offer a timed refill.

For most residential applications brine fill last is just common practice which creates its own potential problems... temperature variances causing salt sludge, evaporation causing low salting etc...

In general brine fill first is very important when using potassium chloride. Sodium chloride... either is fine.

 

[Treeman]

Thank you dittohead. Since Gary no longer posts here, I thought I might stir the pot a bit to remind you of old times.

I know that you advocate removing iron before the softener and prefer the gravel bed system. Its the right way to do things and allows most efficient operation of the softener.

I was limited to purchasing local brands/models available at our jobbers. The Charger softener that I purchased is marketed as "The Iron Breaker". For better or worse, it is a WS1 turbolator model and the brine tank comes standard with the Res-up system.

In all fairness, with my water conditions, our old turbolater unit lasted over 18 years with no rebuild/resin replacement and it kept the water in acceptable condition at 8 lbs./cu. ft. salt, recharged not over 8 days.

 

[ditttohead]

Iron reduction can be very successful with a softener but water conditions must be right. The res-up system really helps these units work much longer by acidifying the brine solution. Unfortunately too many companies learned years ago that softeners remove iron and they proceed without any concern for the environment or the industry. Just like US auto makers in the 70's, efficiencies, the environment and long term industry impact was simply ignored for a quick buck.

The turbulator does not work with a gravel bed. The turbulator creates its own unique set of problems. It also uses a lot more water during the regeneration process due to its higher backwash needs over a traditional system design. And the cleaning action is not as exciting as many companies make it out to be. I have a clear demo unit here with the turbulator in it. It is cute... but not that exciting.

Some people I don't miss Having my own internet stalker gets old real quick. Posting my personal information online, chasing me to other websites etc... I have 3 daughters, I don't need any more drama in my life... lol

 

[Treeman]

I have immense curiosity. Anyone know what the Clack WS1--CH model signifies? It does not have the "P steps" of the CS, but the manual shows that you can program every cycle. Unlike some other models, this one can also do the double backwash.

It looks like this:

 

[ditttohead]

Probably a proprietary valve. Fleck and Clack offer proprietary valves and programming.