Softener sizing

[mccabegc]

I need help folks. I am pulling what little hair I have out of my head trying to figure out what sized softener to pickup. I have read a ton and either, I am not "getting it" or there is conflicting info.

So I have moderately hard water. Just over 5gpg and a low iron content of of .26 mg/l, 3 full bathrooms and a family of 5.

I used the calculator on quality water's website which is a rough number at best. It won't allow me to put in exact numbers so it calculated approx 3000 grains per day. That would be me at 21,000 grains per week. The hiccup comes in when I start reading cu. ft and stuff like that. Shouldn't it be as simple as saying, "I need 21k a week, lets buy a 24k system?

Sorry if I am over complicating this. I just want to get it right the first time. Hefty investment. I will also be adding a sediment filter and carbon block ahead of the softener to deal with some solids and some mild sulfur odors.

Thanks

 

[Reach4]

From the old Gary Slusser calculator, I get this:

Based on the information you entered, 1860 is your Daily Grains of Capacity needed. 14880 is the Total Grains of Capacity you need for approximately once per week regeneration with a 24 hr reserve. 1 is the minimum cubic foot size of softener required for your capacity needs.​

That corresponds to a "32000" grain unit, which you would program to provide 20000 grains of softening per regen. That is more salt-efficient.

 

[Sponsor]

 

[Bannerman]

Beyond the softening capacity which will be consumed, also to be considered is the flow rate needed for your 3 bath, 5 person home.

Adequate contact time is required for ion exchange (softening) to occur. A larger softener utilizes a larger diameter tank and a greater volume of resin thereby increasing the flow rate supported. A 1 cuft softener, will generally support up to 9 gpm continuous flow whereas 1.5 cuft will support up to 10 gpm & 2 cuft, up to 12 gpm.

As all 3 bathrooms could be utilized at the same time while meals are also being prepared and possibly the dishwasher also running, the softener size chosen should support the flow rate needed for your larger home. While the rated flow maybe exceeded on occasion thereby 'leaking' some hardness through the softener, that situation should not be planned when the softener is being chosen. Your larger home should likely require a 2 cuft softener to satisfy the flow rate required.

In addition, salt usage may be made more efficient if only a portion of the total softening capacity is consumed prior to each regeneration cycle. For instance, a 2 cuft (64,000 grain) softener would require 30 lbs of salt to regenerate 60,000 grains capacity (=2,000 grains/lb). If programmed to regenerate when 40,000 grains has been consumed, then only 12 lbs salt would be needed (=3,333 grains/lb).

As you mentioned 'picking up' a softener, I assume you plan to purchase at Lowes, HD or other big box store. FYI, big box softeners are considered by most participants on this site as being of low quality, having a low expected life span. The softener controllers most recommended are Fleck and Clack brands paired with domestic tanks and resin.

 

[mccabegc]

Beyond the softening capacity which will be consumed, also to be considered is the flow rate needed for your 3 bath, 5 person home.

Adequate contact time is required for ion exchange (softening) to occur. A larger softener utilizes a larger diameter tank and a greater volume of resin thereby increasing the flow rate supported. A 1 cuft softener, will generally support up to 9 gpm continuous flow whereas 1.5 cuft will support up to 10 gpm & 2 cuft, up to 12 gpm.

As all 3 bathrooms could be utilized at the same time while meals are also being prepared and possibly the dishwasher also running, the softener size chosen should support the flow rate needed for your larger home. While the rated flow maybe exceeded on occasion thereby 'leaking' some hardness through the softener, that situation should not be planned when the softener is being chosen. Your larger home should likely require a 2 cuft softener to satisfy the flow rate required.

In addition, salt usage may be made more efficient if only a portion of the total softening capacity is consumed prior to each regeneration cycle. For instance, a 2 cuft (64,000 grain) softener would require 30 lbs of salt to regenerate 60,000 grains capacity (=2,000 grains/lb). If programmed to regenerate when 40,000 grains has been consumed, then only 12 lbs salt would be needed (=3,333 grains/lb).

As you mentioned 'picking up' a softener, I assume you plan to purchase at Lowes, HD or other big box store. FYI, big box softeners are considered by most participants on this site as being of low quality, having a low expected life span. The softener controllers most recommended are Fleck and Clack brands paired with domestic tanks and resin.

Sorry I was not more clear. I have zero intention of buying from a big box store. I have already done enough research to know that those units are over priced and low quality.

Sizing my new softener is my main concern at this time. I was thinking of a Fleck 7000sxt unit. Of course as I was reading last night, I found that the "brand name" is not always the manufacturer of the entire unit but merely the manufacturer of the controller. Now I am on a mission to find a vendor with quality tanks and resin. Baby steps lol.

Is there a website or a guide to the math you used? I am a numbers guy but am having a tough time wrapping my head around the numbers. Based upon Reach's response I should be looking at a unit around 1 cu ft, 32000 total grain cap set to 20000 grain regen. What parameters were used for you to suggest 2 cu ft 64000 grain capacity? I really hate the marketing ploys of these companies. It would so much easier if the info was laid out in black and white.

Thanks for any info you can give.

 

[Reach4]

This is from page 1 of Gary Slusser's former sizing pages:
Softener Sizing Chart

IMPORTANT: There are two parts to correctly sizing a softener; capacity and service flow rate (SFR). Look at it like a balance beam scale. On one side is the SFR and on the other is the capacity. The capacity is adjustable by changing the salt dose in a given volume of resin. The SFR is based on the volume of resin and the volume of resin dictates the size of the tank. A softener has to be sized by its (SFR) to be able to successfully treat the peak demand gpm that your plumbing can deliver. If the SFR is exceeded, the softener will not remove all the hardness and iron.

The SFR in gpm is: 1.0 cuft = 9, 1.25 = 10, 1.5' = 12, 2.0' = 13, 2.5' = 18, 3.0' = 20, 3.5' = 22 gpm, 4.0 = 25. FYI, the flow rate from a 100' of 3/4" pipe at 50 psi is 17.5 gpm, for 1", it is 37 gpm. At 30 psi, 3/4" is 14 gpm and 1" is 28 gpm. Of course you will not get that much flow if you have the same ID pipe because your plumbing includes tees and elbows and valves and the fixture risers are much smaller, but if your peak flow rate exceeds the SFR of the softener, all of the hardness and iron etc. in your water will not be removed.

To get an idea of the SFR you need. Your bathtub or an outside faucet will probably have the highest individual fixture flow rate and is an excellent place to calculate part of your total flow rate. Using a bucket, with the hot and cold water running full flow, collect water in a container for exactly 6 or 10 seconds and then physically and accurately measure the amount of water. Then multiply the volume by 10 or 6 to calculate the volume for 60 seconds which is the gpm. This is only the gpm of that tub and doesn't include other water that may be used normally while the tub was filling. If the tub has an anti scald mixing valve then use an outside faucet instead of a tub. Or you can collect the flow for one minute. Once you have the gpm figure find the softner size you need from the above data.

Formula for determining compensated hardness: Hardness in gpg + ((iron ppm or mg/l * 4) + (manganese ppm or mg/l *2)) = compensated hardness round to next higher gpg. Example: 14 gpg + Fe .8 ppm * 4= 3.2 gpg + Mn .6 ppm *2 = 1.2 gpg = 14+3.2+1.2=18.4 rounded to 19 gpg = compenstated hardness.

Capacity calculation: # of People times 60 gals/person/day + all extra water use in gallons/day IE horses etc. multiplied by the compensated hardness = grains/day. Grains/day * 8 (days) for a once per week regeneration (if less than 1 ppm iron; 3 days if you have over 2 ppm of iron) plus a day of reserve (not needed for twin tank models) = the total grains of capacity you need. Then from the chart below find the capacity at the best salt dose that just covers your total grains needed.

Example: 3 people *60= 180 + 10 gals/day for a horse = total 190 gals/day, * 19 gpg compensated hardness = 3610 total grains/day. Then 3610 * 8 days = 28880 total grains needed. Using the salt dose capacity chart below you find the volume of resin that produces 30,000 grains of capacity using 6 lb /cuft of resin. That gives you great salt efficiency and covers your capacity requirement. As long as the SFR of that size softener is correct, you have a properly sized softener with great salt efficiency.

The 6 lb/cuft salt dose gives you 3333 grains of capacity per lb of salt used rather than the maximum salt dose per cuft of 15 lb which generates only 2000 grains per lb of salt. If you use potassium chloride instead of regular softener salt (sodium chloride) and you are using the low salt dose below you may have to increase the salt dose a few pounds.

Sizing Capacity of various salt doses PER CUFT of regular resin. Fine mesh and SST-60 resins are more efficient and are a good choice if you have more than 2 ppm of iron.

EX: 1.5 cuft using a 6lb/cuft (9lb) salt dose generates 30000 grains (3333 grains/lb); 10 lb/cuft (15lb) = 40500 (2700 grains/lb) etc.

 

[Bannerman]

I appear to have misstated the flow rate supported for 1.5 & 2 cuft, as per info which Reach4 has now provided.

Fine mesh resin is rarely recommended as fine resin will often physically reduce the flow rate possible through the softener.
SST-60 is often considered not worth the cost for the modest benefit it may provide in iron reduction. Your iron quantity is not excessive to be a major concern but each 1 ppm of iron is equal to 5 grains (85.5 ppm) hardness when calculating the compensated hardness rate.

 

[Reach4]

Also, when you have a softener do the iron removal, there is treatment and cleaning required on a continuing basis. You would start with the special iron-treating version of salt. But ResCare dispenser and/or Super Iron Out treatment may be called for.

When treating for iron with a softener, you want to regenerate more frequently. So with iron, you don't want to make the softener bigger than you need. You will want to regenerate at least every 7 days probably.

A backwashing filter before the softener can not only remove iron, it can remove other things such as hydrogen sulfide (smells) with the right media. Even if you decide to not put in such a filter, you might place the softener such that you leave room for such a potential filter later.

 

[mccabegc]

based upon my iron levels, .24 mg/l I believe without looking at the report, how much of a concern will iron removal be with my new softener?

I will get a representative flow number from a tub this evening and hopefully I can start to piece this system together. Like I said, I have been looking towards a Fleck 7000sxt but have not decided on that. I am still continuing my research so that I choose the best option for my application. It would appear from what I have read thus far, a vendor selling a quality bundle will be tougher decision.

I am beginning to wrap my head around it all. Thanks

 

[Reach4]

based upon my iron levels, .24 mg/l I believe without looking at the report, how much of a concern will iron removal be with my new softener?

Not much. If you don't need to remove something other than iron, the softener will do it. You may only need to use the special salt. Some people ask a softener to remove 2 mg/l, which is the same as 2 ppm, iron. They have much more cleaning to do.

I would still get some Super Iron Out, if only to deal with existing staining. I would put maybe 1/2 cup into a toilet tank before leaving for a weekend, and similar into the bowl (then close the lid) if you have staining there. Smell is not so nice, but not terrible.

 

[ditttohead]

A larger softener (2 CF) to accommodate the potential flow rates, relatively low salting and a drip chemical system to help the resin last with the moderate iron reduction and you will do fine.

 

[mccabegc]

ok, it took me a little while to get back. I have 3 baths in the house, but only 1 has a tub. The others are stall showers. The bath tub filled a 3 gallon bucket in 48 seconds. So for the sake of whole numbers, 3.5gpm.

So accounting for potential flow rates as ditto stated and also using the data that reach broke down for me. Would it be overkill to go with a fleck 7000sxt 64k total grain system set for 20k regen? Again, I acknowledge the potential flow rates of having 3 bathrooms, a dishwasher, washer etc. I am not sure how this will break down into salt efficiency etc.

thanks again for all of your help folks

 

[Reach4]

There is a range of softeners that will do the softening job. I think a little smaller softener will regenerate more often. While more frequent regeneration when using the softener for iron removal is often recommended, I can't say that the 2 week or so regeneration interval with a 2 cubic ft softener would not work out acceptably for .26 mg/l iron.

I will also be adding a sediment filter and carbon block ahead of the softener to deal with some solids and some mild sulfur odors.

I think the carbon block filter is going to be a problem. You are worried about whether 12 GPM through the softener is enough, and yet you are thinking about putting your water through a carbon block filter? That is going to be restrictive. The GPM ratings for carbon block filter elements is going to be for when the element is new.

I got a backwashing Centaur Carbon-based filter to deal with sulfur smell and iron both. It is very effective for me. I also sanitize my system, and I use a powered anode in the water heater to prevent potential H2S generation there. It protects the WH nicely. The powered anode was probably not needed, but I ordered that before deciding to get the backwashing filter.

 

[mccabegc]

There is a range of softeners that will do the softening job. I think a little smaller softener will regenerate more often. While more frequent regeneration when using the softener for iron removal is often recommended, I can't say that the 2 week or so regeneration interval with a 2 cubic ft softener would not work out acceptably for .26 mg/l iron.

I think the carbon block filter is going to be a problem. You are worried about whether 12 GPM through the softener is enough, and yet you are thinking about putting your water through a carbon block filter? That is going to be restrictive. The GPM ratings for carbon block filter elements is going to be for when the element is new.

I got a backwashing Centaur Carbon-based filter to deal with sulfur smell and iron both. It is very effective for me. I also sanitize my system, and I use a powered anode in the water heater to prevent potential H2S generation there. It protects the WH nicely. The powered anode was probably not needed, but I ordered that before deciding to get the backwashing filter.

ugh, I should absolutely stick to wastewater lol. Say I go with a backwashing filter as you did. Should that be sized to match the softener? Since iron removal is required and there are potential concerns the 64k system will not backwash often enough should I go back to your original specs of the 1cu ft system?

I honestly like the idea of a backwashing carbon filter but was looking away from that route because all of my numbers were so low. However, being in wastewater I understand that sulfide odors happen and low concentrations. I was hoping that a simply wall filter setup would be sufficient. I overlooked the fact that the filters max flow is when new and that will diminish over time.

 

[mccabegc]

and would a greensand filter maybe not be better for my situation since there is also some manganese in my water?

 

[Reach4]

Ditttohead is a pro. I am not. Much of what I know is from what he has posted.

You are getting past the easier answer (how big of softener do I need).
In selecting a backwashing filter, you will also want to look at the service flow rate. Note that if your flow exceeds the rating on occasion, that is not a big deal.

Here is what I think I might do if I wanted to start without knowing what I would want to end up with. I would get a 1.5 cubic ft softner preceeded by 2 4.5x20 Pentek big blue housings in series. I would put in bypass valves on the BB housings in case there is a failure. I have 3 BB in series with no bypass, but I keep spare O-rings. I keep the first housing with no cartridge. I ordered the BBs before deciding to get the backwashing filters.

I would leave space for a backwashing filter to be added later. I would sanitize my well and plumbing system if I see a stretch of nice warm weather days coming. That will reduce H2S for a while. The first line of https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ has a link to a nice sanitizing article, but then I go into my possibly-overkill extension.

 

[mccabegc]

Reach, thank you for you help and your honesty! Ditto and I have been in communication and my new system has been ordered!

1.5 cu ft softener and 1.5 cu ft katalox filtration. (No chemical feed at this time)

Ditttohead is a pro. I am not. Much of what I know is from what he has posted.

You are getting past the easier answer (how big of softener do I need).
In selecting a backwashing filter, you will also want to look at the service flow rate. Note that if your flow exceeds the rating on occasion, that is not a big deal.

Here is what I think I might do if I wanted to start without knowing what I would want to end up with. I would get a 1.5 cubic ft softner preceeded by 2 4.5x20 Pentek big blue housings in series. I would put in bypass valves on the BB housings in case there is a failure. I have 3 BB in series with no bypass, but I keep spare O-rings. I keep the first housing with no cartridge. I ordered the BBs before deciding to get the backwashing filters.

I would leave space for a backwashing filter to be added later. I would sanitize my well and plumbing system if I see a stretch of nice warm weather days coming. That will reduce H2S for a while. The first line of https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ has a link to a nice sanitizing article, but then I go into my possibly-overkill extension.