New system setup, iron softener with KDF

[MagKarl]

First let me say that I really appreciate the folks here that contribute. I've been reading here as a guest for several months now as I've been leaning toward getting a water treatment system and learned quite a bit from you. Most other subjects you can find several different info sources and discussion forums for DIY, but water treatment is difficult to find good info. I feel more confident in the info gained from this site than what I have been able to get from my local water treatment professionals. So however arrogant or ignorant it may be, I've given up on those guys and ordered a system online and signed up here.

I have a well that gives good water other than taste, smell, and staining the showers. Tests clean from a health standpoint. I get about 12gpm out of it.

Hardness about 6gpg, iron about 1ppm, some H2S in both hot and cold. pH is about 7.5. I drink it, my wife and kids don't. I clean the showers, and I've had it. The iron staining is a real pain.

The pros around here all recommend softeners with a little bit of KDF. I was going to get a Water Right Sanitizer Plus but instead decided to go generic for a fraction of the cost.

I ordered a 1.5cf 48K iron softener. Fleck 5600SXT with fine mesh resin and 15lbs of KDF. I chose 15lbs because that's about what's in a Sanitizer plus 1054 tank.

One of the subjects I'd like some input on is the setup in terms of balancing water/salt efficiency with resin life. I understand the compromise and backwash challenge with fine mesh resin and KDF. With my compensated hardness of 10ish gpg at a rate of about 500 gals per day, my daily softening load is 5000 grains. I should be able to cover that at 6-8lbs/cf salt and a weekly regeneration. Is weekly regeneration with my levels of hardness, iron, and H2S reasonable and going to give me long media life? I know I can't use Iron Out with the KDF. Is there any reason to regenerate with more salt than the charts say you should need? Should I be regenerating more based on a number of days instead of by capacity?

[water solutions]

I ordered a 1.5cf 48K iron softener. Fleck 5600SXT with fine mesh resin and 15lbs of KDF. I chose 15lbs because that's about what's in a Sanitizer plus 1054 tank.

Well if you already ordered it, good luck. First of all 15lbs is not a little KDF. It is very heavy given that it will only provide about an inch of media for the sulfur water to travel through. Secondly, it will not backwash thoroughly due to its weight. It will drop to the bottom of the tank under the resin and will begin to channel. Eventually, it will solidify. It will work initially, but will fail after a given time, volume and quantity of sulfur to be removed.

Imagine taking a 15lbs of pennies and grinding them up into a course pile of grain-like media. Throw them into a ten inch wide bucket. Now put a hole in the bottom of the buck and place a garden hose and put about 4 gpm through the media. There is no chance that you are going to lift the heavy media to adequately backwash it. Water WILL go through it in a geyser-like fashion but only in isolated sections. After doing that a hundred times or more, water will still channel through the same locations but the rest of the media will start to bond together and solidify. Eventually, it will become rock hard and even turning the softener tank upside down will not be able to clear it out to replace it.

The sections of the KDF that does not lift during backwash will still struggle to remove sulfur until it is overloaded (READ: even heavier with flow-restricting tendencies) and compounds the problem.

If you set the backwash rate adequate to lift the media (12-14 gpm) then the light weight of the fine mesh resin would cause it to just piston to the top of the tank and it would not backwash properly. One or the other will fail.

A one-system-cures-all usually fails all. KDF does have fine qualities but is often misused.

[MagKarl]

Do you have a recommendation for the max flow rate I can backwash the fine mesh resin?

I know this is a compromise situation and I may learn some tough lessons. The Water Right system puts the KDF on the bottom and claims that since the water has already passed through the resin by the time it gets there, the KDF does not see the constant load of the raw water that it would in a KDF only system. Time will tell. If it fails, I'll rebed with something else or add separate equipment for dedicated functions.

Do you think brine/salt concentration will affect this either better/worse? What would you suggest to maximize my chances of success?

[Tom Sawyer]

Bottom, top, no difference as WaterSolutions already said, most of the KDF will be on the bottom of the tank within 3 months and yadda yadda yadda, every caution that WS gave you is pretty damn valid. I hate the decision you made to mix medias. Separate filters are almost always a more economical and better working solution in the long run. Do yourself a favor and trade the KDF for more resin, then handle your iron and H2S problem separately

[ditttohead]

Agreed, the mixing of medias, especially KDF should never be done except for marketing purposes. 15 pounds of kdf in a 10" tank is 2" of media, how much contact time do you think it will have? http://kdfft.com/images/kdf_POESheet.pdf see this link for detailed information on KDF and its applications, including backwash rates, bed depths, flow rates, etc. 15 pounds for a whole house system is basically nothing. The minimum we recommend is 30 or more pounds, and that is for chlorine removal, nothing more. For iron or hydrogen sulfide, contact time is key. Check out my system, the third tank is KDF, it has 24 pounds of KDF as a chlorine prefilter to the 2 cu. ft. Catalytic GAC filter. Backwash rates are critical as is bed depth.

Let us know what results you get with the equipment. Many times systems will work when they shouldnt. I have installed birm on water supplies in excess of 25 ppm iron, 5 years later, still working. But, we try to keep our numbers within the manufacturers recommendations to ensure the customers do not call back with complaints or desiring a return.

[MagKarl]

I appreciate the input. I know some of you are probably shaking your heads, but this is how I work. Even though this may or will fail, I still want to do what I can to understand what I can influence and make every effort to have it set up with the best chance of success. When it fails, I'll know better what I want. All I can say is I had 4 different guy out to the house and all recommended all in one type systems with KDF saying that's what works well in this area, so that's what I bought. I will definately be hanging around and will report out how it goes.

Can any of you guys give me an idea on what my max theoretical backwash rate ought to be for fine mesh resin? Temp is 50-55F. Is 50% expansion a good target? I can change my DLFC and get to 50% pretty easily if the chart for bed expansion I found online is applicable to my resin. Do most fine mesh resins behave similarly or does it vary greatly between vendors?


I'm considering a swap to regular resin instead of the fine mesh in order to backwash better. What kind of flow rate/sq ft can regular resin go for the same 50% expansion? I have read that fine mesh can be backwashed at a lower rate, but no numbers for either type. I'm still working on the plumbing, so I have time to dink around with the equipment before I install it.

[ditttohead]

Dont take the advice in a personal way, we are just letting you know from our collective experience what to expect, and that your system design has a very well known and documented flaw. My own system is designed specifically to address these know flaws.

The problem is not the fine mesh resin backwash rate issue. That is usually in the 4 GPM per Sq. Ft, range, give or take depending on water temperature, regular mesh resin has a 5 GPM per sq. ft. backwash rate. The issue is the KDF. It requires 25-30 GPM per sq. ft to backwash. Just check out the link to KDF I sent you to determine the proper backwash rates. A 10" tank with fine mesh resin is set to approximately 2.0 GPM backwash, a regular resin is set to approximately 2.5 gpm backwash, a kdf media tank requires approximately 15 gpm to backwash... not a good mix. If you notice my prototype system, the 4 different medias are in 4 different tank sizes, this allows the backwash rates to be accurate across all 4 medias. you cant do that with a single tank design. http://www.terrylove.com/forums/show...ight=prototype My system has the KDF in a 7" diamater tank, the resin is in a 14" diameter tank and the carbon and Turbidex are in 10" diameter tanks, all controlled with a single control valve Your other possible option is the use of a media guard in the system. At least that will properly backwash the KDF assuming you use a 4 gpm flow control at your water temperature and force the water through 4 seperate chambers of KDF giving the media a slight chance at working. KDF dumped into a tank, and improperly backwashed will usually fail in a short amount of time. Water will simply channel around the media, and it will usually start to clump up into little cement like balls in the bottome of the tank. KDF is an amzing media, but it must be used and applied properly. I have yet to see one professional on this sight recommend your method. Their is a good reason for that. We know from years of field experience what works most of the time, and what fails most of the time. Your system design is usually the type that fails. Most people dont know that it failed because they dont know the KDF has stopped working in a few months due to the lack of backwash. The KDF is usually added as a marketing tool rather than a functional media. The only way for it to work as described is for it to be applied as recommended by the manufacturer. Or at least applied in a way that is close to the manufacturers recommendations.

[MagKarl]

Thanks, I'm grateful for the input. I don't intend to argue, just learn.

Any thoughts on a Filox system either ahead of or instead of this unit? I might be able to exchange it. Softening is a nice to have, but the iron and H2S ae high priority.

[ditttohead]

Filox/Pyrolox based units are great but... they require considerable backwash water. The backwash rates are similar to KDF, and filox/pyrolox should be backwashed every 2-3 days. If you have the backwash water available, you will like pyrolox.

[Tom Sawyer]

My area has heavy iron. I wish I had a dollar for every Filox or Pyrolox system that someone installed on a pump that was incapable of supplying enough volume to backwash it. It turns into a solid lump in the bottom of the tank and money out the window.

[ditttohead]

Tom, you couldnt be more correct. I think the real problem is in the poor marketing and application literature of one of the two medias mentioned. That and people not checking to see if their pump system can handle the backwash requirements. The claim of a backwash rate of 15 GPM per Sq. Ft. causes all kinds of problems. They should never be backwashed with less than 20, preferably 25+ GPM per Sq. Ft. and it must be backwashed regularly, (every 2-3 days in most applications). The good thing is the backwash water cna usually be distributed on the lawn with some testing. it usually does not hurt anything, but... do some testing first and check with your local code to see if it is legal. Technically, it can be classified as "Grey water". When Pyrolox is installed correctly, it is an amazing media. Installed incorrectly, it will fail. The problems with Pyrolox is almost the exact same problems people encounter with KDF.

[water solutions]

My area has heavy iron. I wish I had a dollar for every Filox or Pyrolox system that someone installed on a pump that was incapable of supplying enough volume to backwash it. It turns into a solid lump in the bottom of the tank and money out the window.

I just intercepted a customer who had a Pyrolox filter (10" x 44) that lasted about one year until his pressure dropped to near zero. By-passed it and pressure resumed. I explained why that was happening but he called the company back to 'fix' the problem. I will call him tomorrow to see what they did but i would lay cash down that they replaced the media with the same...only to do it again next year? Yes, it solved his water problem but only for a short period of time and his cost in maintanng it will eventually become a PITA if not prohibitive.

[ditttohead]

That is a common problem when the backwash rate is not done at 25 GPM PSF minimum. I prefer 30 GPM PSF. Can their pump system handle the 15 GPM that is needed to properly backwash their system? Can their valve backwash that much? Good luck on this one.

[MagKarl]

I will recheck my flow rate this weekend to see exactly what my pump can handle.

Other than backwash flow rate challenges, the only other caution I've found for Filox/Pyrolox systems is mention of ORP sensitivity for higher iron/H2S levels. None of the water treatment guys or even testing labs in my area have the ability to make an ORP assessment for me. I would be willing to buy a probe if you guys think that is going to be critical. I don't know if my relatively low levels of iron and H2S can be handled without additional oxidizer at this point.

[ditttohead]

You are correct, a certain ORP level is needed for Filox/Pyrolox to function properly. Check out this link, it is an excellent read and will tell you how to test for ORP with a simple Pot Perm test method. You can buy pot perm cheaply online, and this test is accurate. I would highly recommend ignoring their backwash rate recommendation of 12 GPM per Sq and instead backwash it at 25 GPM per Sq. Ft. http://www.premium-water-filters.com...ts/Filox-R.pdf