Fleck 5600, or larger? (7000?)

[colgate2004]

Hi all,
I am new to water softeners and while I've done a good bit of research, I'm still not entirely confident of my choice.

My wife and I live in a 2-1/2 bath home. It's just the two of us for the time being, but we are anticipating kids.

We are on a well with effectively zero iron, manganese, copper, or arsenic (the water lab test results were below the test result minimum thresholds for each) and approx 200 ppm(mg/L) or ~12.3 grains/gallon hardness.

We don't use much water: we both take pretty quick showers, don't have any crazy "rain" heads, etc. The combined water use of the 2-unit apartment building where we used to live was about 5500 gallons per month, and that was for my wife and I plus the three people living above us, leading me to believe that my wife and I use about 35-40 gallons of water per day each.

Those numbers would seem to indicate we only need a very, very small softening system... 40gal * 2 people * 12 grains * 7 days = a mere 6720 grains... even if we double that for eventual kids, we're still barely at 15,000 grains.

On the other hand, I am one of those people who always over-sizes systems... to decrease strain, increase lifespan, maybe increase efficiency, etc.
I see though that higher-grain softening systems waste more water in each regeneration than lower-grain systems (some specs I've seen are in the range of 20 gallons for a 24K system versus 50 gallons for a 48K system), which leads me to believe that bigger, in this case, may not be better.

The system I am currently leaning toward is a Fleck 5600SXT valve in 24K, 36K, or 48K (all easily available for under $600).

I am also concerned though about pressure drop: I do like high water pressure from my faucets and showers, and I've read that the more resin (the higher the grain #), the more pressure drop will result.

I would greatly appreciate the advice of those more knowledgeable than myself!

 

[Bannerman]

A softener does not need to regenerate every week when there is no iron present. Regeneration could be as few as 1X per month so a higher capacity unit could deliver your soft water requirements for several weeks before regeneration becomes necessary.

Although the backwash gpm will be higher for a larger diameter tank, fewer regeneration cycles per year will more than makeup for the slight increase in water used for each regeneration of a larger unit. To compare, the backwash flow rate required for a softener with a 9" tank diameter (1 cuft = 32K grains total capacity) is 2 gpm vs 2.4 gpm for a 10" tank (1.5 cuft = 48K grains total). Backwash will typically run 10 minutes per cycle and Rapid Rinse will use the same flow rate for 5-10 minutes/cycle. The longest runtime will be during Brine/Slow Rinse which is usually less than 1 gpm for 60 minutes, regardless of the softener capacity appropriate for your needs.

As no iron is present, a larger softener will also provide higher salt efficiency. For example, a 1 cuft unit would require 15 lbs salt to regenerate 30K grains usable (ie: 2K grains per lb) whereas a 1.5 cuft would require only 9 lbs to deliver the same 30K grains (3,333K/lb). Higher capacity will allow higher gpm to household fixtures with no hardness leakage through the larger resin bed.

A 1 cuft unit would use 6 lbs salt to regenerate only 20K grains capacity to obtain the same 3,333 grains/lb efficiency or, 8 lbs salt to regen 24K grains for 3,000 grains/lb efficiency.

Using your 40 gals, 2 people and 13 grains/gallon hardness (12.3 is more than 12), 20K capacity would be expected to regenerate (20K / 1040) = 19 days approx. With 30K usable capacity, regeneration would be expected to be approx 28 days for 2 people.

A 0.75 cuft is not typically recommended whereas a 1.5 cuft softener would allow for a larger family as well as occasional houseguests.

 

[Sponsor]

 

[colgate2004]

Bannerman,

Thank you very much for your reply. The efficiency is definitely something I don't understand... I don't understand how to calculate how many pounds of salt a given size system will use to regenerate a given number of grains. I'll take your word for it though on all the numbers you gave me above.

Given that, it seems the only question left is about the pressure drop: If a 1.5cf 48K system would have a noticeably higher pressure drop than a 1.0cf 36K system.

Thank you very much for your help.

 

[Bannerman]

If a 1.5cf 48K system would have a noticeably higher pressure drop than a 1.0cf 36K system.

A higher capacity softener uses a larger diameter tank, thereby keeping the water path through resin bed roughly the same distance regardless of the amount of resin. If the resin column height was increased, I expect you would then experience a noticeable decrease in flow rate. Fine mesh resin, however, is typically not recommended as FM can pack tighter and will often increase flow resistance compared to standard mesh resin.

In case you are considering it, softeners sold online typically do not include a gravel underbed and so will often include a shorter tank. Underbeding is highly recommended as it helps to distribute water flow through the entire resin bed diameter, thereby assisting water flow through the softener and also allowing more capacity to be utilized from the resin before hardness leakage occurs.

Here's a link which provides further details regarding capacity, efficiency and hardness leakage.

https://view.publitas.com/impact-water-products/2018-catalog-final/page/66

 

[colgate2004]

Ah ha, I understand about the tank diameter's impact on the flow rate, thank you.

I am planning on buying the unit online, as I'm in a rural location and there aren't much in the way of brick-and-mortar stores (much less specialty water treatment vendors) near me.
The unit I'm planning on buying comes with a 10"x54" tank... does that sound like one of the shorter tanks that would not use a gravel underbed?

As I understand from a different thread, the tanks that have gravel underbeds only use a couple of inches of gravel (it isn't supposed to fill more than the bottom domed section of the tank)... could I just put some gravel in myself when assembling the system if the unit I order doesn't come with gravel?

 

[ditttohead]

Avoid the online companies pushing the ultra low prices, stick with a slightly higher priced unit at minimum. Most of the online companies are battling each other for the lowest price by using the lowest priced components including junk media, garbage tanks, even counterfeit valves. I take several calls every week with questions on why my house is full of resin (broken bottom screen) or why the tank neck is leaking (Cheap tank) or why the water tastes like fish (resin from lowest bidder), why did I lose water pressure (6% or lower crosslink resin even though they claimed 10%), why is the valve leaking (Counterfeit Valve), why do I have air in my house after every regeneration (Overseas cheap brine tank-float assembly), etc...

The race to the bottom is very fun to watch!

 

[colgate2004]

Unfortunately I don't know what qualifies as an "ultra low price" versus a "slightly higher" price!

The unit I'm looking at at least *claims* to include a genuine Fleck valve (I see pictures of two different designs that claim to be the Fleck 5600SXT... one is symmetrical, the other has the display and buttons set off to the left...?)...

 

[ditttohead]

Its not just the valve, every other component is available from some very lousy manufacturers. Even something as simple as the bottom screen can cause serious problems a few years later. Check out the pictures of the counterfeit Fleck bottom screen on this page from our catalog. This is a very common problem. These knock offs are available from overseas for about 50 cents. My 5 year old daughter can crush them with her hands.

 

[zer0]

A softener does not need to regenerate every week when there is no iron present. Regeneration could be as few as 1X per month so a higher capacity unit could deliver your soft water requirements for several weeks before regeneration becomes necessary.

Although the backwash gpm will be higher for a larger diameter tank, fewer regeneration cycles per year will more than makeup for the slight increase in water used for each regeneration of a larger unit. To compare, the backwash flow rate required for a softener with a 9" tank diameter (1 cuft = 32K grains total capacity) is 2 gpm vs 2.4 gpm for a 10" tank (1.5 cuft = 48K grains total). Backwash will typically run 10 minutes per cycle and Rapid Rinse will use the same flow rate for 5-10 minutes/cycle. The longest runtime will be during Brine/Slow Rinse which is usually less than 1 gpm for 60 minutes, regardless of the softener capacity appropriate for your needs.

As no iron is present, a larger softener will also provide higher salt efficiency. For example, a 1 cuft unit would require 15 lbs salt to regenerate 30K grains usable (ie: 2K grains per lb) whereas a 1.5 cuft would require only 9 lbs to deliver the same 30K grains (3,333K/lb). Higher capacity will allow higher gpm to household fixtures with no hardness leakage through the larger resin bed.

A 1 cuft unit would use 6 lbs salt to regenerate only 20K grains capacity to obtain the same 3,333 grains/lb efficiency or, 8 lbs salt to regen 24K grains for 3,000 grains/lb efficiency.

Using your 40 gals, 2 people and 13 grains/gallon hardness (12.3 is more than 12), 20K capacity would be expected to regenerate (20K / 1040) = 19 days approx. With 30K usable capacity, regeneration would be expected to be approx 28 days for 2 people.

A 0.75 cuft is not typically recommended whereas a 1.5 cuft softener would allow for a larger family as well as occasional houseguests.

Hmm I would be careful with prolonging regen periods like you suggest. Once a month is ludicrous. The resin bed needs to be fluffed and flushed at regular intervals to kill bacteria and remove microbiological buildup. Once a week is standard, once every 2 weeks is about max. This is regardless of tank size or capacity of system.

 

[ditttohead]

So how does every exchange tank program in the country that runs on a monthly schedule work? I design and build regen plants, we design the tank sizes based on monthly routes, it is much more important to sanitize the systems annually as recommended by every manufacturer than to regenerate weekly. Bacteria grows in all water, controlling the amount of bacteria is the key.