First, your criteria:

1. Metered regen control: Agreed, this is the best way to go.
2. Counterflow regen: No - Not unless you are planning on a Kinetico or other packed bed softener. Counter-flow regeneration only works properly in a packed bed. Most softeners are NOT packed bed. The Fleck softeners you referenced certainly wouldn't be without some sort of special order. Packed beds come with potential problems of their own and I would only suggest their purchase from a company that normally provides them.
3. Proportional regen: Provides some salt efficiency at the expense of softener performance and reliability. This requires water to be added to the brine tank a couple of hours prior to regeneration, which results in a weak brine (It takes 48 hours to get saturated brine in a stagnant tank). That weak brine is less capable of regenerating the softener, resulting in more hardness bleed.
4. Double backwash: Not necessary unless you have lots of sediment in your water (in which case get a sediment filter instead), really high water pressure (in which case install a regulator), or a very large softener. Plus it makes the softener less water efficient.

Since you are interested in maximizing water AND salt efficiency, there are a few things you can do:

1. Purchase a larger softener than you need so it will need to regenerate less often. This will save water.
2. The balance point between water and salt efficiency is at a regen salt dosage of 6 lb salt/cubic ft of resin. However, you can reduce your salt dosage to as low as 3, provided you do not have ferrous iron in your water. That low setting will result in some hardness bleed. It will be low, but you might notice a difference in water feel. Salt saving will be minimal, ~1 lb/month. The tradeoff is more frequent regeneration, but that can be mitigated by purchasing a larger softener.
3. You can reduce your reserve to zero and either potentially live with some hard water for most of a day, or allow your softener to regenerate whenever it happens to hit capacity and live with some hard water for a couple of hours every once in a while. At a salt dosage of 6 lb/cubic ft, this would save you ~4 lb salt per month.

Assuming you use 100 gallons of water per day, a softener sized to regen weekly at a salt dosage of 6 lb/cu ft will use 22 lb salt/month, or 14 lb at a salt dose of 3 lb/cu ft. A larger softener, sized to regen every three weeks with no reserve at a salt dosage of 6 lb/cu ft will use 19 lb salt/month or 12 lb at a salt dose of 3 lb/cu ft.

NOTE: The above only applies if you do not have iron your your water.

Thanks for the comprehensive reply, Alice! I can confirm that iron is not an issue, full chemical lab test results came back at only .01 mg/L iron content, which I believe translates to something along the lines of .172 gpg for softening purposes.

You bring up a salient point in regard to counter-current regen requiring a packed bed to avoid fluidization. I do remember reading something about this in the early stages of my research, but had since glossed over it. A couple of additional questions on this point:

1. Is a packed bed strictly necessary for technical reasons in a counter-current regen situation, or is it simply desirable in order to fully capture the brine efficiency and final polisher effects of the lowest portion of the resin bed being the most highly recharged? I ask only because I have seen several online sellers of full softener systems which included the Fleck 5600SXT valve configured for upflow regen, but have seen no references to these systems including a packed bed tank. I should probably contact these sellers with a follow-up question to that effect.
2. Is resin loss during backwash in a counter-current regen scenario a concern? If so, would an upper distributor prove sufficient to prevent this?
3. Would adjusting the backwash gpm settings be a workable solution to prevent over-fluidization of an unpacked bed?

Your explanation of the proportional regen feature is the first reference I have read regarding the feature forcing a softener to both work harder and less efficiently, resulting in higher hardness bleed. Interesting. Thanks for bringing this up.

My interest in the double backwash feature appears to run counter to some of the others from an environmental standpoint. My interest stems primarily from the fact that I do have some sediment in my water (I'm considering a spin-down filter installed upstream of the softener as well), and if I cannot locate a Fleck 5600SXT or Fleck 6700XTR configured for upflow, I've read that double backwash will somewhat mix or fluidize the resin bed, resulting in less hardness bleed and channeling.

Your tips on ways to maximize salt and water efficiency all make perfect sense. After performing some initial calculations in the early phases of this project, oversizing the softener stood out to me as well as a primary means of increasing salt and water efficiency. The oft-recommended regeneration frequency of every 7 days raised my eyebrows, as even for my lean household this would lead to ridiculous levels of salt and water consumption.

That said, I've also read plenty about the risks and inefficiencies caused by oversizing a softener for an intended application. It seems that the primary risks here are those of fouling the resin (primarily caused by water with iron and/or sediment content) and channeling due to low flow rates. I don't think I'll have an issue with resin fouling due to iron, and I plan on combating sediment with the aforementioned spin-down filter upstream of the softener.

I think the channeling issue has a much higher chance of being an issue for my application. I've installed low-flow water fixtures throughout my house: adjustable 0 - 1.5 GPM shower heads, .5 GPM faucet aerators in the bathrooms, adjustable .5 / 1.0 / 1.5 GPM aerator on the kitchen sink. Energy Star-rated dishwasher (3.3 gal/cycle), clothes washer (10 gal/cycle), and fridge. Toilets are currently 1.6 GPF units with bolt-on bidets installed, but I plan on replacing both toilet units shortly with dual-flush models consuming approximately .9 GPF for liquids.

While I've calculated theoretical maximum flow rate requirements approaching 7 GPM currently (two showers on max, kitchen sink on max, dishwasher and clothes washer filling) with the potential to rise to 8.5 GPM in future (additional shower to be installed in finished basement once kids are older), realistic flow rate is currently much more likely to live within a range of .5 GPM - 1.6 GPM 95% of the time, with the majority of usage at a rate of 1.0 - 1.5 GPM (kitchen sink), 1.0 - 1.5 GPM (showers), or 1.6 GPM (toilets).

I've read that in order to limit channeling, you should size a system to flow at least 3 GPM per square foot of resin bed area. Most 48,000 grain units such as the Fleck 5600SXT come with a 10" x 54" resin tank, which translates to an ideal flow rate of 1.975 GPM to combat channeling. This obviously exceeds my realistic flow rate of approximately 1.5 GPM, which has me concerned. However, if I look at stepping down to a 40,000 grain (1.25 cu. ft. resin) unit with a 9" diameter tank, sacrificing regeneration frequency for less risk of channeling, the ideal flow rate is still 1.78 GPM. I'd have to move all the way down to a 32,000 grain (1.0 cu. ft. resin) unit on an 8" diameter tank to even get close (1.58 GPM) to the ideal range to limit channeling, and at this point I don't think we're willing to use the additional salt and water that would be required for the much higher regeneration frequency.

In the interest of doing what I can to source a system capable of combating channeling, I'm strongly considering the $80 upcharge for a Vortech tank to enable better mixing / fluidization of the resin bed during regeneration, which may also help combat channeling through the resin bed during service while reducing backwash water use.

My current plan involves targeting a 48,000 grain (1.5 cu. ft. of resin) unit, which according to my calculations should regenerate every 20 days at a 5 lb. salt dose per cu. ft. of resin (salt efficiency of 4,000 grains/lb.) and a 5% reserve. This results in estimated salt consumption of .34063 lb/day, 7.12 lb/regen, and 124 lb/year, with estimated water consumption of 3.27 gal/day, 65.4 gal/regen and 1,140 gal/year (calculations do not include the advertised 30% backwash water savings offered by a Vortech tank).

This amount of salt and water consumption results in an increase of the TDS in our source water by about 131%, from 500 ppm to 1153 ppm. The above estimates put daily water consumption attributed to the softening process at about 5.2% of our daily household consumption, a number my wife and I can live with in exchange for all the benefits of soft water and the ability to install a tankless water heater which will, in turn, have a much lower environmental footprint than our current tank-style unit.

The 5% safety factor / reserve capacity used in my calculations amounts to full 24-hour period coverage for us. I would simply reduce this number further as you've recommended and put up with the chance of hardened water for a brief period on high usage days, but my plan to replace our electric tank-style water heater with a tankless natural gas unit immediately after concluding this water softener project probably precludes that. My interest in upflow regeneration is in part due to the lower hardness bleed through rate with the tankless water heater in mind, while my interest in the proportional brining feature arose primarily from a desire to be able to maintain a plentiful reserve capacity to protect the tankless unit, while not sacrificing salt or water efficiency at the same time.

Since my original post, I've discovered that it appears the Fleck 6700XTR was discontinued by Pentair as of March 31st, 2016. It is still available for sale from some online vendors, though my chances of finding upflow configuration Model #42134 available in combination with a Vortech tank and a packed resin bed probably aren't very high. I'm bummed about this, as the Fleck 6700XTR was available in upflow configurations with both variable / proportional brining and variable regeneration and appeared to provide all the features I was hoping for.

Pentair recommends the Fleck 5800-series valves as a replacement for those interested in the Fleck 6700XTR. The 5800 series appear to be marketed as a more modern replacement for the 5600 series, and come in three different port sizes (5800, 5810, and 5812 series) with three different controllers available (LTX, SXT, XTR2). These models are available in upflow configurations, but only the XTR2 touchscreen controller appears to offer variable / proportional brining capability, while checking in at nearly twice the price of the Fleck 5600SXT.

In addition, Pentair appears to have made the decision to market the new 5800-series valves only to dealers, making them unavailable through online retailers or resellers and limiting their availability to the DIY community. At this point my options appear to be as follows:

1. Attempt to source a Model # 42134 Fleck 6700XTR valve configured for upflow and pair it with a Vortech tank, taking the risk of purchasing a model which has been deemed end-of-life.
2. Purchase a system consisting of a Fleck 5600SXT valve configured for upflow paired with a Vortech tank, and live without the variable / proportional brine feature.
3. Purchase a system consisting of a Fleck 5600SXT valve configured for downflow paired with a Vortech tank, and live without both upflow and the variable / proportional brine feature.
4. Pay twice what I would for a Fleck 5600SXT to purchase a Fleck 5800XTR2 which adds variable brining capability.

Top three:

1. Strictly necessary - this according to resin manufacturers technical specifications. The reason you find counterflow regen offered in non-packed-bed softeners is because most folks that sell residential water treatment haven't a clue what they are doing and only read the brochures. To be blunt, they are too lazy or too stupid (or think you are too stupid) to be bothered paying attention to specs and technical bulletins from manufacturers.
2. No more so than the back wash during co-current regen. Backwash is ALWAYS counter-current. The softener tank should be sized to allow the resin bed to be "fluffed" up an additional 50% plus a little extra head room. A top distributor won't prevent loss of resin - it is designed to distribute water more evenly across the top of the bed. A top basket, on the other hand, is nice on well water, but required for city water.
3. Backwash flow rate is determined by resin specifications. Properly sizing the softener prevents loss. Don't mess with the backwash flow rate (it is set by an orifice) or you may not get adequate backwash.

Sediment: if you wish to go longer than a few days between regens, you absolutely MUST remove the sediment upstream from the softer. Sediment from your water or broken bits of resin beads will be the only thing, in your situation, that will cause channeling.

Double vs. single backwash: Either will fluidize the bed if the softener is sized properly.

Water usage: Your household really only uses 63 gallons of water per day total? What capacity were you using for the resin at a 5 lb/cu ft salt dose?

Water TDS: Do you mean total average water TDS down the drain, or do you mean increased TDS of water to the house? If the former, then, yes. If the latter, then it will be 873, an increase of ~75%.

Vortech tank: One of these gadgets will not reduce your backwash by 30%. IYou may be able to reduce backwash time by a little bit, but you won't be able to reduce flow rate. In addition to flow rate based on softener area, all resin manufactures specify the range of time the resin must be backwashed. The way the Vortech marketers come up with that 30% number is by using the maximum of the range for a gravel bed and the minimum (or under) for their gadget. Reality is, a normal softener with a gravel bed will never need to be backwashed the maximum time. What Vortech is really designed to do is charge you a higher fee while the seller makes a lot more profit by not having to ship gravel, which is heavy. You will see little, if any, actual water savings.

Bottom line: In my opinion, if you want a standard softener, get a 5600SXT. The difference in price for the 5800 will never pay for itself in salt or water. If you want counterflow regen and maximum salt savings (but a bit higher water usage) get a Kinetico. Either way, install a sediment filter upstream.

Thanks again for taking the time to weigh in, Alice. It is much appreciated!

I checked out a few resin manufacturer TB's as you recommended, and found that in every case upflow is only recommended in a packed bed setting, confirming your earlier point. This is good to know. A few follow-up questions on this topic:

1. I have found literally zero online sellers who advertise Fleck-based softener systems possessing packed beds. Any idea where I could source a packed-bed tank for use with a Fleck valve?
2. I think I probably already know the answer to this, but I'll ask anyway - If not, would it be possible to fabricate my own packed bed using any readily available resin tank?
3. Your earlier comment regarding backwash flow rate being driven by resin manufacturer specs makes sense. That said, I've read of some within the industry, particularly Clack, who configure their upflow valves in unpacked tanks intentionally with undersized backwash injectors as a work-around. Is it possible / recommended to utilize undersized backwash injectors in upflow regen scenarios lacking packed beds in order to avoid over-fluidization of the resin bed?
4. In your experience, can upflow regen reduce or eliminate the ability to utilize water pressure to drain a water softener vertically? I'm looking at a vertical lift of 5-6' and a horizontal run of 2-3x that to tie in to my main drain line currently.

I plan on addressing any sediment present with the aforementioned spin-down filter upstream of the softener, likely followed by a 50/5 micron dual gradient Big Blue filter downstream of the softener for the primary purpose of preventing any resin loss from the softener passing into downstream plumbing and/or fixtures.

I've since read even more about the complexities involved with successfully capturing the increased efficiencies made possible by upflow or counter-current regeneration. If I ditch this as a system requirement, does this in your opinion make double backwash (as outlined in section two of this link) a more attractive option for increasing effective capacity, reducing hardness bleed, and reducing channeling?

In regards to water usage, you nailed it. My best estimate puts us at 62.5 gpd currently, well under the U.S. average. The capacity I was using for the 5 lb./cu. ft. salt dose was 20,000 grains, total 30,000 grains of capacity for a 1.5 cu. ft. system.

In regard to TDS, sorry, I should have clarified. Yes, I was referring to TDS down the drain.

When it comes to the Vortech tank design, I've heard the incentive for dealers to replace gravel beds with Vortechs before in regard to shipping. Makes sense. I've also read some potential cons in regard to the distributor tube moving out of position during shipment and requiring complete tank replacement.

Your comment regarding resin manufacturers specifying the amount of backwash time makes sense, though I hadn't thought of it before. Perhaps I'll settle on a resin and then work backwards from there to come to a final decision on some of these features. Thanks for the tip.

I'm a pretty dedicated DIY'er, and I hate the idea of being beholden to a dealer for purchase, parts, or service for a system. For that reason, Kinetico, Culligan, and Clack systems are all out the window, likely in addition to the Fleck 5800-series of valves.

It seems as if my options have narrowed to the Fleck 5600SXT, 7000SXT (discontinued, still available) and the 6700SXT (discontinued, still available). I just need to decide if I want to take the risk of an end-of-life valve in the case of the 7000 and 6700 and whether I want to purchase a valve configured for double backwash or not. I'm leaning towards standard downflow regeneration at this point.

https://www.houzz.com/user/schwartzy18510 What system did you end up getting? I am in a similar situation with hardness of around 21.

Hello robinhome! Unfortunately, I can't answer that question, as I ruptured my right Achilles tendon playing city league volleyball shortly after posting. I've been on crutches following surgical repair since and am just now starting to walk again, albeit with a limp. This project has been back-burnered for now, but I hope to have it in place by the end of 2018. I will update this thread with the final results when done. Good luck with your project!

Alice, thank you for all of the detailed information. I currently have a dual tank Kinetico Model 60 that is 17 years old and needs new resin but since it is a proprietary system the local dealer wants $600 to replace the resin. Would you recommend replacing the resin or purchasing a new Fleck 5600sxt which would not be much more expensive?

FYI for those who made be reading this, I have come to the following conclusions based upon my research:

1. Fleck appears to be the most recommended and companies like 602ABCWater provides a 5600sxt with the 10% cross-linked resin. There are more Fleck water softener systems on the internet because the distributors/re-sellers are not limited to a territory and can sell from anywhere to anywhere in the US.

2. Clack distributors/re-sellers cannot sell outside of their territory so there are fewer internet/web offerings. Reduced competition appears to cause the Clack systems to have a higher price than the Fleck systems.

3. Hydrotech / Canature appears to be the primary provider for many of the private brand valves/controllers including the Discount Water Softeners-Genesis, the US Water Systems- Fusion NLT and the Quality Water Treatment-SoftPro. All three of these companies quote the same statistics that promote the "efficiencies" and "cost savings" of an Upflow system vs a Downflow system. These companies also offer a 10 year warranty on the controller compared to 5 years for the Fleck but reading other blogs, it would appear that a Fleck controller can last 15 or more years which would probably outlast your resin.

The answer to your question depends on a few things:

1. Do you have particulates in your water?
2. Well or city?
3. Is there dissolved iron?
4. Do you want to install/rebed yourself or hire someone to do it?

I have to change my softener as well. Here is my situation:

-On a well

-Will install a sediment filter

-23 gpg hardness

-Never seen rust stain anywhere on bathtub, sinks, toilets, so low iron presumably.

-4 people

I was thinking of the following system configuration:

-Fleck 5800 XTR2 head, with #00 injector, 0.125 gpm BLFC, 4 gpg DLFC, 20 psi regulated injector cap, upflow configuration

-13"x54" tank with 2 ft3 of Purolite C100, 0.33 lb of gravel

-12 min of brine draw will give 3.15 lb/ft3 for a capacity of about 17,000 grains/ft3, so just short of 5 days between regeneration.

Should such a configuration perform well for my needs?

Hi pldrouin,

Please start a new discussion instead of hijacking a year old thread.
I'll be happy to discuss with you then.

Sorry since I have the same goal as schwartzy18510 and the last post was in May I thought it was more relevant to ask the question in the same thread to keep the information in the same location...

Please know that Alice is no longer posting on this site.

ok thanks. I created a new discussion as requested and expanded on my original post: https://www.houzz.com/discussions/fleck-water-softener-valve-w-upflow-variable-brine-double-backwash-dsvw-vd~5549904