What is the correct salt setting for 6 people, 20 gpm?
What is the correct salt setting for 6 people, 20 gpm?
that is an extremely complex and open ended question but... For the most part, the industry has landed on 6# of salt per cubic foot, but most field guys know that 8# of salt will give much softer water. If you want I can post the bleed/efficiency curves, but in all honesty, 8# of salt per cubic foot of resin will give accaptable qual;ity and efficiency.
To properly answer your question, we need to know how big your system is, does the water have competing ions, like iron or manganese, how hard your water is, what kind of controller, and how many gallons you average. 60 gallons of water per person per day is common.
8 pounds of salt per cubic foot will yeild approximately 24,000 grains hardness removal.
Hope this helps.
I've been saying 8 lbs for a long time but get shot down and made to look like I don't know what I'm talking about. When using 6 lbs, you must take out the reserve which means you really only have 16k worth of usable resin. I use 8 lb because it makes the math easier. Thanks.
The current setting is 8/10. I rebedded with about 1.25 cf of resin...that was going about an inch above the turbolator DT as suggested by Gary, which is about 2/3 full. The system is a Fleck 5600 controller (metered) with a 10x44 tank, 48,000 grain . Does setting it at a higher rate cause it to also to regen more often, using more water and salt? Boy, this stuff is pretty technical. Thanks for taking the time to help the do it yourself people.
Many years ago, we used to regenerate systems with 15+ pounds of salt per cubic foot per regeneration, this was very bad and wasteful. It should only be done on applications that require <3 PPM hardness like steam boilers. Even then, the softener should be installed in a primary and polisher design so as to maintain similar efficiency, but this is another topic...
Legally you may have to set your system to 6 pounds of salt per cubic foot, but the vast majority of installers bump that up to 8.
Removing the reserve? The reserve is an equation that is based on the singles days usage which is set so the system will regenrate prior to running out of capacity. I do regular training on system capacities, bleed curves, water quality expectations, etc. Wether you regenerate the system with 4 pounds or 18 pounds of salt per cubic foot, you still have to set your reserve, unless you are using proportional brining or twin alternating designs. Even with proportional brining, we recommend the programming have an intermittent "full salt" regeneration done at least every tenth regeneration. I beleive the Watts 7000 based unit does just this. Upflow brining may allow for some minor improvement on this issue, at least on paper, but in the real world, due to the regeneration cycles and the mixing of the bed that occurs prior to salting, and the 2nd backwash that is common on most new systems, the upflow regeneration has dropped in popularity due to the regulated brine complexities.
Most systems calculate the reserve or are easily adjusted so as to accomodate the system regardless of how many pounds of salt that are used. The 5600 "Econominder" still needs to be manually adjusted, but the important thing to remeber is to properly size the systems initially to maintain efficiency
Single tank systems should regenerate no more often than every fifth day, this will allow for acceptable efficiency. Anything past 5 days is more efficient, but only minimally so.
I didnt realize I as droning on this long.
Anyway, simple answer,
6# of salt per cu ft = 20,000 grains, but a hardness leakeage of 6-9 PPM is to be expected after regeneration, near the end of the systems capacity, leakage will increase considerably
8# of salt per cu. ft = 24,000 gains, hardness leakage of 3-4 PPM is to be expected after regeneration
By using a slightly higher amount of salt we have increased quality by 100%, and dropped our efficiency by 10%.
Example, how does 2 lbs less salt per regeneration equate to 16K without us knowing the capacity you start with? Or, how is anyone supposed to know what you meant to say when what you say is incomplete? If your total K of capacity is based on 8lbs getting 24K per cuft, and 20K with 6 lbs/cuft, you made and error of 4K.
To figure reserve, if you use a control valve without variable reserve, you subtract a day's worth of capacity, in this case using 60 gals/person/day and his 20 gpg, that figure is 7200 grains, and you take one day off a day timer or 360 gals (60gals/person/day) off the meter setting of a metered valve. And you regenerate including the 7200 grains in the total K of capacity you program with/for/to. You don't take out the reserve, you must regenerate it.
I never used 8lbs/cuft and 24K or 6lbs/cuft and 20K. I used a salt setting of at least 3333 grains/lb regardless of the cuft of resin. I got very high salt efficiency and no one complained that their water wasn't soft enough. I included a soft water (soap) test with every softener I've ever sold and as long as a test showed 0 gpg, the customer was happy. Plus I was happy rarely having "slimy feeling" complaints.
Here we have a family of 6 and 20 gpg hardness with no iron or manganese. I would use 60 gals/person/day for 7200 grains per day and 5 days between regenerations due to his 1.25 cuft of regular mesh resin. The total regenerated K of capacity would be 36K and operational would be 29K. Total gallons would be 1800 minus the reserve of 360 (one day's worth) = 1440 on the meter; causing a regeneration on average every 4 days. The salt dose to regenerate 36K in 1.25cuft would be 11 lbs.
He says he has a 48K softener but... his tank is a 10"x 44" instead of a 10" x 54" for a 1.5 cuft softener so I say he has a 40K softener but only if he were to use the max salt dose of 15lbs/cuft foot; 18.75lbs
If he had a Clack WS-1 with variable reserve, I would use the 36K, 11 lbs and the full 1800 gals and he gets the same 3333 grains/lb salt efficiency but regenerates on average every 5th day instead of every 4th day which on an annual basis saves a fair amount of water and salt.
It is your OPINION I am wrong. I was taught that when you use 6 lb of salt you get 20k. Take away a reserve of 20% and that's 16K. By using 8 lbs of salt and 20k, I have taken the reserve into account. It has worked for me for the past 22 years. I think I will stick with it.
Gary, Perfectly stated. The technical aspects of softening is where it gets tough, especially super low salting systems and pushing reserves to try to get ridiculoous efficiency standards. A standard system with a proper reserve should regenerate with 15% or more capacity left, which in turn will give you the additional 10+% overhead on the grains/lb salt. Only in systems that are set extremely accurately and in a twin alternating design does this equation have the slightest potential to not work, even so, the hardness is always bumped up a few grains allowing for more safety factor.
The only problems we have are when people run the capacity to tight, which emphasises the hardness bleed. This is most common when people who have a Hach 5B test kit and read too much on how to make a softener the most efficient it can be. You know the customer, the guy who tells you how he adjusted it so it will use less salt because he read online....
This is the way I would set it up since he has a 5600. I have inserted our programming guide we send out with our 5600 system.
5600 10X44 (1-1/4 Cu. Ft.) Softener
Your 40,000 grain system has been factory set as follows:
8# of salt per cu. ft. =10# of salt per regeneration
24,000 grains capacity per cu. ft. = 30,000 grains total capacity
This system is technically capable of 32,000 Grains removal per cubic foot of resin. For salt efficiency, we set the actual capacity to 24,000 grains removal per cubic foot.
Our factory technician has set the valve as follows.
1: set time to 12:00 P.M.
2: Set meter to 1200 gallons
3: set salt to 10 pounds
This may need some fine tuning for your application but it should help.
Wow! That was informative and very helpful. Thanks.
The water softening business sounds promising. Is there a basic course/training?
Most of the knowledge of the water treatment industry is OTJ. There are training courses but they are expensive and make little sense if you do not work with the equipment on a regular basis. I have been in the industry for 25 years and have specialized in industrial, commercial, pharmeceutical, WFI, and electronics quality water. The residential systems is where I got my start and I still develop products for that field. I do training seminars but these are usually limited to people with a minimum 2-3 years experience. I travel all over the world doing seminars and training courses as well as consult with several manufacturers on new product development.
I would recommend starting with basic filtration, small residential RO systems, and slowly work your way into residential equipment. After a couple years, and some very good support from your supplier, many people can succeed in this business. Most will fail though.
Of course it works for you because you are using more salt and reserve than you need to which means the softener is less efficient than it could be.
In this case with a family of 6 and 20 gpg, I say the softener is undersized. I say that due to having to regenerate it every 3-5 days instead of every 7-9 days. Do you agree?
Seems this topic is delicate. Is there a general consensus that my system is undersized? If so, using the same valve, could I just buy a bigger tank, DT and more resin? If so, what size tank? I ask because water around here is expensive!
LOL, salt efficiency and salt settings should not be a difficult or sensitive suspect. It is really quite simple but sometimes people make it much more difficult than it needs to be. The real problem is many people are used to doing it a certain way that has always worked. This is ok but our industry has been under heavy attack due to the lack of system efficiency for many years. Many companies still put out systems that only regenerate every third day, or use timeclocks instead of meters. This type of thinking will give those who want to get rid of our industry more ammo. I have spent years designing systems that are specifically engineered for reasonable, common sense efficiencies. Now many manufacturers are trying to outdo eachother by increasing efficiency percentages by less than a 1/2%. This has lead to some terrible system designs, sort of like cars today. Car manufacturers are bragging that their terrible, expensive, complex design gets 42 miles per gallon, as opposed to that excellent design car that is horribly inefficient at only 40 miles per gallon.
I would highly recommend replacing the entire system with a new unit. The modern electronic control valves by Fleck and Clack will greatly exceed the efficiency of the electro-mechanical Fleck 5600.
Here is my calculation for you.
6 people x 70 gallons x 20 grains hardness x 6 days = 50400 grains / 24000 grains per cu. ft at 8# of salt per cu. ft. regen = 2.1 cu. ft of resin. A 2.5 cubic foot softener would be highly efficient for your application. Now people may argue a different formula but this is a common formula for single tank metered applications. You can probably do just fine with a 2 cu. ft softener but considering the minimal additional cost of the extra 1/2 cu. ft. ...
My preference would be a 13x54 w/ 2.5 cu. ft. and a Fleck 7000SXT or XTR controller. My second choice would be the WS1 valve.
If you are on a municipal supply, I would recommend the stacked system with a 1/2 cu. ft GAC pre filter tank. This is an inexpensive and highly water efficient system design.
Thanks for the info., dittohead. Is this the one?
Fleck 7000 SXT Digital Metered Model 70-SXT-2-80-M Back to Top
1 1/4" Plastic Bypass Included FREE!
Model: 70-SXT-2-80-M Water Softener
Specs: 13x54" mineral tank, .2.5 cu. ft. of high capacity resin, 18 x 33" brine tank, 2310 brine float, salt platform, 1 1/4"* bypass valve, 1" or 1.25" connectors, 7000SXT Fleck* Metered on demand valve, floor space:** 32 x* 18 x 62"
Capacity: 80,000 grains
Shipping Is Free