Fleck 9100 SXT splitting tanks

[Tobey]

So I bought a fleck 9100 SXT a few years ago and installed for whole house. Since they advertised 4PPM iron removal I thought it would be a good fix but turns out it's not great at removing iron. I also have sulfur and magnesium. So I have come up with a plan to separate the two tanks and use one for active carbon and one with the resin pellets for cleaning my pool water when the TDS gets too high.

The problem is, the second tank has an unknown tube size and the adapters I keep buying are too small (o-ring) and will only fit on the first tank. I think this is the correct one now but I don't want to buy another part that doesn't fit. Can anyone verify that this part will work to just adapt the second tank to an NPT fitting in order to remove the first tank? Thanks,

https://www.water-softeners-filters...VbMj0vYhC_5JS3cG9HHQ9aCRqrGTVxPgaArtyEALw_wcB

 

[ditttohead]

That will not work. What resin are you trying to use to clean your pool?

 

[Sponsor]

 

[Tobey]

That will not work. What resin are you trying to use to clean your pool?

The resin is whatever came with the Fleck 9100, tiny brown beads. The adapter is the wrong size? I have the 'yoke' and 'tube' assembly I thought I should be able to use those pieces as long as the O-ring side is the larger size. but they never list the diameter of that side of the fitting.

 

[Bannerman]

A Fleck 9100 is an alternating twin tank water softener valve. Both tanks are to rightly contain water softening resin as the alternate tank will immediately provide soft water once the capacity in the initial tank becomes depleted and requires regeneration.

The minerals most responsible for hardness are calcium and magnesium. Softening resin will remove those mineral ions by exchanging them with sodium ions. As ions are exchanged, TDS (total dissolved solids) will not be reduced but a TDS meter measurement will often indicate higher TDS in softened water as sodium is a better conductor of electricity compared to calcium or magnesium. A TDS meter does not identify which specific elements makeup the reading, but only estimates general TDS based on the electrical conductivity of the water sample.

While a softener can be effective in removing a small amount of iron, there are better and more efficient methods for iron removal. 4 ppm iron is significant so an alternate method(s) will usually be needed.

Suggest posting your complete lab test report for your raw well water so as to receive educated recommendations on treatment methods that are likely to be more effective.

 

[Tobey]

So am I dreaming to use this to help my pool water? I have algae issues and shock / algaecide aren't working well anymore. I saw an ad for mobile pool water RO treatment for areas that have low water usage requirements and thought it could work here since I don't like pumping iron water from the well into my pool as it stains the walls as soon as chlorine is added.

 

[Reach4]

Injecting chlorine, followed by a contact/settling tank with a blowdown valve, sounds like a good thing for this. The chlorine reacts with the iron, and the iron settles out. The blowdown valve lets you flush out the settled iron.

 

[Bannerman]

Iron in well water is typically in a ferrous state (totally dissolved and clear). Chlorine is an oxididant that will rapidly oxidize Ferrous iron, converting it to a Ferric state (red rust). Both iron forms will adhere to items but once becoming oxidized, will become visible.

As R4 suggested, oxidizing the ferrous iron before it enters the pool will allow the resulting Ferric solids to precipitate from the water so they may be eliminated prior to the pool. Depending on the amount of iron, filter media such as Katalox Light will also be utilized to further remove Ferric particles. The strength of chlorine and contact duration and/or other iron removal methods, will be largely conditional on your water chemistry which is why it was recommended to post a current lab test report.

To separate and use each exsisting softener tank separately, will require the 9100 to be replaced with two other control valve models that are each designed for single tank applications such as for a water softener or for a filter.

 

[Tobey]

OK that sounds like an option for my house - add chlorine treatment and blow down (air chamber?). I'll look that up later but I currently have two issues:

1. My well water that feeds the house has iron and sulfur so RO isn't performing well (installed 3 years ago the fleck9100SXT).
My solution: unplug the fleck 9100SXT and use second tank for active carbon. I added #6 gravel and 6lbs of active carbon after removing the resin and it seems to be doing alright so far, never backwash and never switch to RO tank from control - currently running the second tank with the 1st tank attached and need to separate possibly with the fittings used in the first link.

2. Pool water is 3-4 years old and never been changed. Algae is growing quick and it's getting hard to chlorinate and I saw adds for RO pool water treatment so I figured since I'm only using the one tank for active carbon then I should be able to split the 1st tank off and plumb it into the pool filter system for use occasionally. The only issue is again the second tank has different pipe sizes (proprietary O-ring style) so splitting it has become a chore. I'm about to cut the tubes and use hose clamps to attach a flex pipe if I can't find the correct fittings for the second tank which aren't advertised.

Last test results I got showed I recall 4PPM iron .5PPM sulfur, maybe some other insignificant items.

 

[Tobey]

Iron in well water is typically in a ferrous state (totally dissolved and clear). Chlorine is an oxididant that will rapidly oxidize Ferrous iron, converting it to a Ferric state (red rust). Both iron forms will adhere to items but once becoming oxidized, will become visible.

As R4 suggested, oxidizing the ferrous iron before it enters the pool will allow the resulting Ferric solids to precipitate from the water so they may be eliminated prior to the pool. Depending on the amount of iron, filter media such as Katalox Light will also be utilized to further remove Ferric particles. The strength of chlorine and contact duration and/or other iron removal methods, will be largely conditional on your water chemistry which is why it was recommended to post a current lab test report.

To separate and use each exsisting softener tank separately, will require the 9100 to be replaced with two other control valve models that are each designed for single tank applications such as for a water softener or for a filter.

OK so maybe just emptying pool and re-filling with treated water will be best. I've already removed the iron from the pool water so was hoping to just get rid of some TDS / nitrates but doesn't look like that's the best option.

 

[Bannerman]

A water softener (ie: your twin tank unit using Fleck 9100 control valve) is not a Reverse Osmosis system nor is it a filter.

RO is a type of filter system that utilizes a semi-permiable membrane that will remove dissolved solids that are too large to pass through the membrane. The membrane will not collect and hold rejected solids so the membrane will require constant rinsing with fresh water so as to flush away rejected solids to drain.

hoping to just get rid of some TDS /

Water will evaporate from the pool leaving any dissolved solids behind. Replacing the evaporated water with new will further add additional dissolved solids so TDS will continue to rise unless the water is replaced completely or an actual RO is utilized.

 

[Reach4]

One thing I had forgotten to add... chlorine is bad for softener resin. When chlorine is used to remove iron, it is usually followed by a backwashing carbon tank to remove residual chlorine before the softener. Are you sure you need softening? It seems like a shame to remove chlorine soften, and add chlorine again.

https://www.swimuniversity.com/calcium-hardness/

 

[Tobey]

A water softener (ie: your twin tank unit using Fleck 9100 control valve) is not a Reverse Osmosis system nor is it a filter.

RO is a type of filter system that utilizes a semi-permiable membrane that will remove dissolved solids that are too large to pass through the membrane. The membrane will not collect and hold rejected solids so the membrane will require constant rinsing with fresh water so as to flush away rejected solids to drain.


Water will evaporate from the pool leaving any dissolved solids behind. Replacing the evaporated water with new will further add additional dissolved solids so TDS will continue to rise unless the water is replaced completely or an actual RO is utilized.

JEESH I thought it was an RO system so I guess I screwed up buying that thing.. So I guess I should switch gears and run the single softener tank followed by the active carbon tank and maybe the softener will help keep the active carbon good for longer? Then I'll just have to drain the pool and refill with fresh water either filtered or with a sequestering agent to prevent staining (when added before filter since I'm not sure I want to waste lifespan for cleaner pool water).

 

[ditttohead]

The softener is not used to make the carbon tank work better or last longer. I am not sure where you are going with your treatment but unless you get a real water test done, there really is nothing we can do other than give you wild guesses. Use this link and get the well standard...
NTLWATERTEST

 

[Tobey]

Yeah I guess I'll have to spend a lot more $$ the water was smelling bad like sulfur, and I have iron staines - those are the main reasons I was wanting to treat it. The house inspection when I bought it only tested for nitrates, but I had a water company come and test it for free but can't seem to find the results I think he just told me on the phone (couple years ago) during a sales pitch.

Active carbon seems to be doing its job for the moment with the sulfur smell and I'll have to wait and see on the staining. Pool is being drained and I'll fill it back up from my sprinkler well which I don't notice sulfur smell in but I do believe it has significant iron so I'll probably be dealing with pool staining again unless I can rig up some settling tank / chlorinator but I'm not really all that excited about throwing down another $1k for filtering.

 

[Gsmith22]

OP, the thread is somewhat confusing because of the domestic water and pool requirements being intertwined in the discussion - its all over the map and its hard for someone to help across the internet if you are unsure of what you actually have or need. Begin with the water test as dittohead recommends for domestic water.

Might want to head over to troublefreepool for pool stuff. Iron in the pool water is bad for staining as you recognize, but shouldn't otherwise cause algae growth. Do you monitor your CYA level? Too much CYA makes chlorine (whether sourced via tablets, bleach, salt water generator, etc.) ineffective. A small amount of CYA is good so the sun doesn't kill off the chlorine but once you get above a certain amount, the chlorine levels need to go way up to control algae. Lots of the prepackaged pool store chlorine sources come with CYA embedded so if you keep adding them, over time your CYA goes into the stratosphere (especially if you don't monitor it) and no amount of chlorine will work effectively making your pool un-sanitized. Only thing to do at that point is drain the pool to get rid of the CYA (although rain and subsequent draining down pool will dilute and eventually drop the CYA level over time if more isn't added but this could take a year or more). For filling your pool, there are lots of water supply companies that show up with tanker trucks to fill pools where I am at if you don't want to use well water with iron and hardness that haven't bee extracted. look up pool filling online. probably will pay like $0.10 a gallon for the water (order of magnitude).

 

[Tobey]

gsmith22 Thanks for the response. Very good point about the CYA, it's something I hadn't considered.

I ordered the fittings in the link posted and they will work - the ones in the link above can split the tanks and allow me to use one tank for active carbon on my house water, and the other to remove the calcium from the pool water and use manual regen. I think since I use calcium hyperchlorinate 78% I should at least be able to reduce the calcium that gets added as it's a lot cheaper than sodium hypo at the pool store.

Not sure if the softener will remove CYA but I did drain the pool about 70% and refill with water from my sprinkler well (maybe not so bad on the iron) and haven't noticed any additional staining. I had residual chlorine (2ppm) and the solids (algea and dust) promptly settled out. I was able to filter some but it mostly stirred it up so I set up the vacuum and pumped it out the second time and the water is looking good now. Added a little more chlorine and will vacuum out the sediments again hopefully will be good to go.

I'll check the CYA if this happens again - I do have a kit and last I checked it was about 100 but that was 6 months ago. The floater tablets have CYA too and may have increased it too high.

 

[Reach4]

I ordered the fittings in the link posted and they will work - the ones in the link above can split the tanks and allow me to use one tank for active carbon on my house water, and the other to remove the calcium from the pool water and use manual regen. I think since I use calcium hyperchlorinate 78% I should at least be able to reduce the calcium that gets added as it's a lot cheaper than sodium hypo at the pool store.

That does not read right. Adding calcium adds calcium.

Have you looked at a chlorine generator?

 

[Gsmith22]

CYA at 100 is way too high. Recommended levels vary depending on pool type and source of chlorine (half that amount would be much better) but I would try to base all of your pool chemical ranges on this: https://www.troublefreepool.com/blog/what-are-my-ideal-pool-levels/

I don't think CYA is removed by a softener - I would assume Ca, Mg, Fe, and probably any other positively charged metal ions would be. But you don't want all of your Ca removed - it just needs to be in balance with pH and the other chemicals. This is especially true if you have a concrete/plaster pool. If you take all the Ca out of the water in a pool with a plaster finish, the water will leach Ca our of the plaster destroying it. Balance is what you want, not 0 Ca. The link I provided tells you the range you want for Ca.

How are you testing your water? If test strips, throw them out. they are useless and get the titration test kit recommended on troublefreepool or direct from Taylor (troublefreepool sells Taylor stuff made for pool testing at cheaper prices then you will find elsewhere). Test all chemicals at least weekly and pH and chlorine daily and use this link https://www.troublefreepool.com/calc.html to determine what chemicals you need to add/removed to bring the pool water back into balance.

Dealing with domestic well water is a breeze compared to keeping pool water in balance. Its a full time job.

If you are using tablets, then yes, they have CYA in them. CYA doesn't leave the water so it just keeps accumulating. Which is why you don't want to use tablets. Frankly, if you don't have a chlorine generator, I would just use regular household bleach for my chlorine source. But chlorine generators are great. I have one and highly recommend it.