Water Softener Size Needed for my Situation?

[Neil Wilson]

I would like help in determining the size of water softener needed for my situation.


Well Water
3/4" incoming water line
35.5 grains/gal hardness (determined by two test)
01.2 grains/gal of iron guess (.1 to .4 ppm in one test; 0 in second test)
36.7 grains/gal total (hardness + iron)
150 gallons/day water usage (2 people @ 75 gal/person)
38,537 grains/7days softening requirement

Based on 38,537 grains/7 days requirement, I think I should get a 1.5 cu/ft water softener with 3/4" input/output ports. And, it should be programmed with a Capacity of 40K. I don’t know what the salt setting should be?

If I am correct, then will the Fleck 5600 SXT 48,000 grains works? Is there a better choice?

I have had three sales people visit/test/quote. Their proposals include smaller sizes and are about three times the cost. Am I not seeing something?

 

[Bannerman]

You seem to have most of this figured out.

The 5600 design is several decades old and although reliable, easy to service and popular, it has limitations including a maximum backwash rate of 7 gpm thereby normally limiting its use to backwashing filters with 10" or smaller tanks. For a softener application, it is suitable for softeners with up to a 12" diameter tank which is 2.0 cuft, normally marketed as 64,000 grains total capacity. As your requirements are within those specifications and as your home is equipped with 3/4" plumbing, the 5600 should work well for you but Fleck also produces the 5800 and 5810 models which could also be considered since they are current designs which exceed the capabilities and features of the 5600 SXT.

With regard to capacity, salt setting and efficiency, below is a link to chart which indicates various salt setting and usable capacities for a large range of softener sizes. At the bottom of the chart is shown a comparison of Grains per Pound efficiency for each salt setting.

Although your weekly consumption is within the capacity of a 1.5 cuft softener, you may wish to consider a 2 cuft unit for lower salt use and improved efficiency. 2 cuft of resin will deliver 42,000 usable grains when regenerated with 12 lbs salt (6 lbs/cuft) for a maximum salt efficiency of 3500 grains per lb, whereas 1.5 of resin will require 22.5 lbs (15 lbs/cuft) to regenerate 45,000 grains capacity (2,000 grains/lb)

https://terrylove.com/forums/index.php?attachments/resin-chart-jpg.53316/

 

[Sponsor]

 

[Neil Wilson]

You seem to have most of this figured out.

The 5600 design is several decades old and although reliable, easy to service and popular, it has limitations including a maximum backwash rate of 7 gpm thereby normally limiting its use to backwashing filters with 10" or smaller tanks. For a softener application, it is suitable for softeners with up to a 12" diameter tank which is 2.0 cuft, normally marketed as 64,000 grains total capacity. As your requirements are within those specifications and as your home is equipped with 3/4" plumbing, the 5600 should work well for you but Fleck also produces the 5800 and 5810 models which could also be considered since they are current designs which exceed the capabilities and features of the 5600 SXT.

With regard to capacity, salt setting and efficiency, below is a link to chart which indicates various salt setting and usable capacities for a large range of softener sizes. At the bottom of the chart is shown a comparison of Grains per Pound efficiency for each salt setting.

Although your weekly consumption is within the capacity of a 1.5 cuft softener, you may wish to consider a 2 cuft unit for lower salt use and improved efficiency. 2 cuft of resin will deliver 42,000 usable grains when regenerated with 12 lbs salt (6 lbs/cuft) for a maximum salt efficiency of 3500 grains per lb, whereas 1.5 of resin will require 22.5 lbs (15 lbs/cuft) to regenerate 45,000 grains capacity (2,000 grains/lb)

https://terrylove.com/forums/index.php?attachments/resin-chart-jpg.53316/

I am concerned about the discharge volume for a regeneration. Is there a way to determine that volume is for a given softener? My septic system is at 1/3 capacity currently.

 

[Bannerman]

A softener's media (resin) is relatively light in weight compared to other media such as those used for iron removal. As such, a softener will require a significantly lower flow rate to backwash the resin compared to the backwash requirements for most other media.

Water treatment usually involves compromise. While higher salt efficiency will require less salt for a given amount of capacity, the frequency of regeneration will need to increase in the same size softener since the capacity setting will need to be lower.

The most recommended salt settings are either 6 or 8 lbs per cuft of resin as those provide a good balance of salt efficiency, water quality and regeneration frequency. While a larger softener will require slightly more water for regeneration, the amount of discharge may actually be less each year since regeneration will occur less frequently when the softener is programmed to deliver higher capacity.

Here are typical stages of regeneration and discharge expectations:
Backwash: usually 10 minutes duration @ 2.4 gpm for 10" diameter tank or 3.5 gpm for 12" tank
Brine Draw (includes Slow Rinse): 10" - 0.83 gpm for 15 minutes + 0.45 gpm for 45 minutes, 12" - 1.4 gpm for 15 minutes + 0.85 gpm for 45 minutes
Rapid Rinse: Same flow rate as Backwash. Usually 10 minutes but often may be reduced to 3-5 minutes
Brine Fill: Water entering the Brine tank at a rate of 0.125, 0.25, 0.5 or 1 gpm. Volume is determined by the salt setting for the capacity to be regenerated. Each gallon will dissolve 3 lbs salt. This liquid is drawn into the softener during 1st 15 minutes of Brine Draw.

Some softeners are configured to perform 2 Back Wash cycles, 1 before Brine Draw, and 1 after.

There was a university study posted on this forum some time ago that indicated softener discharge into a septic system is not harmful to the system, and may actually be helpful to the septic bacteria when an efficient salt setting is utilized.

 

[Reach4]

I am concerned about the discharge volume for a regeneration. Is there a way to determine that volume is for a given softener? My septic system is at 1/3 capacity currently.

Add together the minutes for backwashes and fast rinse. Multiply the sum by the DLFC gpm. That would typically be 2.4 gpm for a softener with 1.5 cuft of resin. The minutes can be programmed. I might set those times to 5+5 minutes, but the initial defaults are commonly higher. So anyway, that is 24 gallons. If optimizing for less water use, you might cut those times some more.

Also the injector takes water. That would commonly be about 60 minutes, and that might be about 0.25 to 0.33gpm... so another 15 to 2o gallons typically. Brine fill might be another 4 gallons.

I don't know what it means for a septic system to be at 1/3 capacity. Regen normally happens in the middle of the night, after the water use for the day has probably already gone out into the field.

 

[Neil Wilson]

A softener's media (resin) is relatively light in weight compared to other media such as those used for iron removal. As such, a softener will require a significantly lower flow rate to backwash the resin compared to the backwash requirements for most other media.

Water treatment usually involves compromise. While higher salt efficiency will require less salt for a given amount of capacity, the frequency of regeneration will need to increase in the same size softener since the capacity setting will need to be lower.

The most recommended salt settings are either 6 or 8 lbs per cuft of resin as those provide a good balance of salt efficiency, water quality and regeneration frequency. While a larger softener will require slightly more water for regeneration, the amount of discharge may actually be less each year since regeneration will occur less frequently when the softener is programmed to deliver higher capacity.

Here are typical stages of regeneration and discharge expectations:
Backwash: usually 10 minutes duration @ 2.4 gpm for 10" diameter tank or 3.5 gpm for 12" tank
Brine Draw (includes Slow Rinse): 10" - 0.83 gpm for 15 minutes + 0.45 gpm for 45 minutes, 12" - 1.4 gpm for 15 minutes + 0.85 gpm for 45 minutes
Rapid Rinse: Same flow rate as Backwash. Usually 10 minutes but often may be reduced to 3-5 minutes
Brine Fill: Water entering the Brine tank at a rate of 0.125, 0.25, 0.5 or 1 gpm. Volume is determined by the salt setting for the capacity to be regenerated. Each gallon will dissolve 3 lbs salt. This liquid is drawn into the softener during 1st 15 minutes of Brine Draw.

Some softeners are configured to perform 2 Back Wash cycles, 1 before Brine Draw, and 1 after.

There was a university study posted on this forum some time ago that indicated softener discharge into a septic system is not harmful to the system, and may actually be helpful to the septic bacteria when an efficient salt setting is utilized.

Very good - I wanted to calculate the gallons of water entering my septic system for each regeneration. I used your 10" x 54" tank information and came up with the following for the discharge gallons:

1 backwash - 10min. @ 2.4 gpm = 24
2 brian draw w/Slow Rinse - 15 min @ 0.83 gpm plus 45 min @ .45 gpm = 32.7
3 fast (rapid) rinse - 10 min. @ 2.4 gpm = 24
4 brian fill - rate of 0.125, 0.25, 0.5 or 1 gpm = 0 discharge gallons since this water does not go down the drain

80.7 total discharge gallons (i.e water which goes down the drain to my septic system) for a given regeneration.

If my calculations are incorrect, please let me know my error.

 

[Neil Wilson]

Add together the minutes for backwashes and fast rinse. Multiply the sum by the DLFC gpm. That would typically be 2.4 gpm for a softener with 1.5 cuft of resin. The minutes can be programmed. I might set those times to 5+5 minutes, but the initial defaults are commonly higher. So anyway, that is 24 gallons. If optimizing for less water use, you might cut those times some more.

Also the injector takes water. That would commonly be about 60 minutes, and that might be about 0.25 to 0.33gpm... so another 15 to 2o gallons typically. Brine fill might be another 4 gallons.

I don't know what it means for a septic system to be at 1/3 capacity. Regen normally happens in the middle of the night, after the water use for the day has probably already gone out into the field.

Very good - Please note that my septic system currently has only one leach line (two leach lines are out of use) - so 1/3 capacity.

I am thinking that when you say "injector takes water" that that is 2 step (i.e. after the initial backwash). My adjusted calculated discharge gallons is:

1 backwash - 5 min. @ 2.4 gpm = 12
2 brian draw w/Slow Rinse - 15 min @ 0.83 gpm plus 45 min @ .45 gpm = 32.7
3 backwash - fast (rapid) rinse - 5 min. @ 2.4 gpm = 12
4 brian fill - rate of 0.125, 0.25, 0.5 or 1 gpm = 0 discharge gallons since this water does not go down the drain

56.7 total adjusted discharge gallons (i.e water which goes down the drain to my septic system) for a given regeneration.

If my calculations are incorrect, please let me know my error. I reduced the time for step 1 and 3 (backwash) from 10 to 5 minuets. Does this have much of an effect on the quality of the regeneration?

Yes, I understand that the regeneration will be in the middle of the night. That is good. It will take 80 mins. (70 mins with reduced backwash time). I am thinking that my 1/3 capacity septic system can handle the 56.7 adjusted discharge gallons. And, it could likely handle the 80.7 full discharge gallons.

 

[Bannerman]

A concern with a 10" tank (1.5 cuft) is your calculated usage and the effect of the far greater amount of salt in your septic system.. You indicated needing 38,537 grains/week which a 2 cuft softener will satisfy while using a very efficient salt dose. A 1.5 will require almost 2X the amount of salt to satisfy your requirements.

4 brian fill - rate of 0.125, 0.25, 0.5 or 1 gpm = 0 discharge gallons since this water does not go down the drain

The water that enters the brine tank will dissolve salt into a brine. That brine will be discharged to drain during the Brine Draw/Slow Rinse phase of regeneration. The higher flow rate indicated in the 1st 15 minutes of Brine Draw, represents the brine being drawn from the brine tank.

I am thinking that when you say "injector takes water" that that is 2 step (i.e. after the initial backwash).

Water during the Brine Draw/Slow Rinse phase of regeneration, will flow through the injector at the lower flow rate indicated above. As the injector acts as a venturi, the slow flow of rinse water through it will create suction on the brine line to draw brine from the brine tank to the softener tank. Once all of the brine has been drawn from the brine tank, a valve (air check) at the bottom of the brine tank will close to prevent air from being drawn into the softener. When the air check is closed, rinse water will continue to slowly flow through the injector for the remaining programmed time so as to push the brine through the resin bed to the drain while also rinsing the resin.

 

[Reach4]

2 brian draw w/Slow Rinse - 15 min @ 0.83 gpm plus 45 min @ .45 gpm = 32.7

What injector are you presuming? I think #0 is better than #1 for this. #00 would be good to, tho you might increase BD to 80 in that case.

 

[Bannerman]

What injector are you presuming?

I suspect he is referring to my earlier post #4. 0.83 gpm is the combined flow rate for a #1 White injector as specified in the Fleck 5600 & Econominder Service Manual as appropriate for a 10" diameter tank.

The regeneration flow rates and timings included in post #4 were intended only as examples, to give Neil an idea of the typical stages and amount of water and time required for regeneration. Since the equipment has not yet been chosen, this was not to state how Neil's equipment will be specifically configured.

 

[Neil Wilson]

Hello Bannerman and Reach4,
My knowledge of water softeners started at zero a few weeks ago. I then got three local shops to give a sales pitch (water test/proposal). The costs of their proposed systems seemed to be many times more than buying a Fleck 5600SXT 1cu/ft softener. So, I am learning more to understand what I really need.

The first proposal was for a $1880+installation Brita Pro Gold system (1 cu/ft; 3/4" Turbine Meter; Upflow cleaning). After pressing for answers, the sales person has indicated that the system capacity would be set at 25000 and a regeneration would discharge less than 50 gallons. My calculation is that a regeneration would be required every 4.6 days (25000 capacity / 5505 my daily grains).

After doing Internet research, I found I had more questions than answers. I then found this site and posted this thread.

From the information provided by the two of you, it looks like I need a 2 cu/ft softener to work best regarding yearly water and salt usage. Below are my calculations for regeneration drainage. This is my main concern given my septic system is on 1/3 capacity (i.e. only one leach line):

Water Softener Regeneration Water Usage - 12"x52" tank = 2.0cu/ft resin
Regeneration frequency = (40000/5505) = 7.3 days

1 backwash - 10min. @ 3.5gpm = 35 gal.
2 brine draw w/slow rinse - 15min @ 1.4 gpm plus 45min @ .85gpm = 59.25 gal.
3 fast (rapid) rinse - 10min. @ 3.5gpm = 35 gal.
4 brine fill - rate of 0.125, 0.25, 0.5 or 1 gpm 0

Total drainage/regeneration = 129.2 gal.

Adjusted - Water Softener Regeneration Water Usage - 12"x52" tank = 2.0cu/ft resin
Regeneration frequency = (40000/5505) = 7.3 days

1 backwash - 5min. @ 3.5gpm = 17.5 gal.
2 brine draw w/slow rinse - 15min @ 1.4 gpm plus 45min @ .85gpm = 59.25 gal.
3 fast (rapid) rinse - 5min. @ 3.5gpm = 17.5 gal.
4 brine fill - rate of 0.125, 0.25, 0.5 or 1 gpm 0

Total drainage/regeneration = 94.25 gal.

I understand that step 4 brine fill uses water which is not sent down the drain until step 2 of the next regeneration. Is that correct? Maybe I can test running 129.2 gallons of water down my drain over 1.5 hours and watch my septic tank to see if there is a problem. This would eliminate or confirm my fear regarding my septic system. It would be good to have the best yearly water/salt usage possible. If my septic tank fear is confirmed, then more system configuration is needed.

Any additional thoughts you two have are appreciated.

 

[Bannerman]

As I anticipate your septic situation will be repaired to restore full function, it would be inappropriate to base a long term purchase (water softener system capacity) on a temporary situation.

One item I had neglected is high hardness compensation. Your hardness is more substantial than most and so your softener will not work as efficient as when the hardness is lower. As such, there is a compensation factor that will need to be considered which will further increase the amount of hardness to be programmed so as to compensate for the inefficiency. I expect Reach4 has that calculation in a spreadsheet format and so he can advise on the calculation changes necessary for your specific amount of hardness.

The flow rate information I provided was obtained from one of the Fleck Service manuals, as an example of what you may expect. As Reach4 had mentioned, the injector to be installed may often be exchanged with an alternate size. When the injector is changed, the slow rinse and brine draw flow rates will be altered and so the program time may need to be modified to compensate, but sometimes, this can be beneficial.

I'm not certain how you determined 150 gallons/day usage. While that amount is at the upper end of the usual consumption estimates for 2 people (50 - 75 gallons/day/per person), if your home is equipped with newer efficient fixtures and appliances, your consumption may be lower than anticipated. Since the softener will measure the actual amount of water flowing through it, regeneration will occur when the softener's programmed capacity has been consumed.

 

[Reach4]

understand that step 4 brian fill

This is the first time I have seen a spellchecker change brine to brian.

While your septic may or may not have a problem (mine has no problem with the softener drainage), there is something called a dry well that you could consider. If you cannot run the drain to the dry well below the frost line, it is possible to design the piping to keep the drain pipe empty until it spews water. Water should not freeze because it will not have time before it all drains. Another possibility would be to have a pressure relief feed its output to the septic field while the dry well accepts the water most of the time. Just thinking.

 

[Neil Wilson]

Bannerman and Reach4,
Thank you for your information. Yesterday I installed a new well water pump. First step toward resolving water issues. My original goal was to install a UV unit to eliminate coliform found in my well water (we currently use bottled water). Internet research indicated that hard water needed to be eliminated prior to using a UV. Thus my water softener research began.

Yes Bannerman, it makes since to get a correct water softener rather than an incorrect softener that works with my problem septic system. Now that I know the total drainage water for a correct water softener (94 to 120 gal.), I can hopefully determine if my septic system will work as is or must be replaced first. This will take several months and is likely a 20K cost given current county regulations.

As far as my 150 gal. of daily water use - that was just a guess based on Internet research. Yes, I used the high end of 75 gallons per person.

I didn't find any Internet information regarding "high hardness compensation". Any direction on how I determine this is appreciated. I am using 35.5 gpg (plus 1.2 gpg for iron) noted by one shop. Another shop noted 30 gpg. I need to somehow do my own test is guess since gpg of hardness is an important entry for setup.

Reach4, if I determine my septic can't handle the drain water, I will investigate the dry well requirements. Also, I have a sump pump in my crawl space which could handle the softener drain water. It dumps onto the grass in the back yard. Internet opinions are different on this subject. Some say "no problem for grass" some say "kills grass". What is your thinking?

FYI - "brian" was my mistake (corrected above).

 

[Reach4]

Thank you for your information. Yesterday I installed a new well water pump. First step toward resolving water issues. My original goal was to install a UV unit to eliminate coliform found in my well water (we currently use bottled water). Internet research indicated that hard water needed to be eliminated prior to using a UV. Thus my water softener research began.

For deep wells, I think in most cases the coliform test fail reason is not being thoroughly sanitized after well work, or contamination during sampling. https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ is my writeup. It may be overkill, but I think overkill is appropriate.

Reach4, if I determine my septic can't handle the drain water, I will investigate the dry well requirements. Also, I have a sump pump in my crawl space which could handle the softener drain water. It dumps onto the grass in the back yard. Internet opinions are different on this subject. Some say "no problem for grass" some say "kills grass". What is your thinking?

I expect it is a problem for grass that you don't want to risk killing.

 

[Neil Wilson]

For deep wells, I think in most cases the coliform test fail reason is not being thoroughly sanitized after well work, or contamination during sampling. https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ is my writeup. It may be overkill, but I think overkill is appropriate.

I have a dug well (about 15'). I tested the well after a flood (5 years ago). There was 1.5' of water in my crawl space. So, the well had about 5' of extra water due to the water table. After testing, I used chlorine to "clear" the well. But it still tested to have coliform. We have been using bottled water since. I was hoping a UV would provide a clear test. If I can install a water softener and UV using the current septic system, then I will proceed. I feel I now know that I should use a 2 cu/ft softener. Current septic capacity seems to be the next step. If I need to redo the septic system as a next step, then the softener/UV will become a lower priority.