Greensand Filter Backwash Problem


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Old 03-25-08, 09:09 AM
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Question Greensand Filter Backwash Problem

Recently installed greensand filter system model 2510 (fleck?) with 3200 timer successfully removed the sulfur smell from well water in an accessory structure on my property. However, after each backwash cycle (every 6 days) a purplish color is in the toilet bowl after one flush. It takes seven flushes of this low-flush toilet to clear the water (the color is the dye in the manganese I think). The installer has been out twice, adjusting the quick rinse cycle time. Any thoughts about what's going on or how to remedy? thanks... a reluctant do-it-yourselfer.
 
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Old 03-25-08, 10:50 AM
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Purple Water

Potassium Permanganate is the regenerant used in these systems. If the regenerant is not rinsed completely after regeneration, then you can have a purple/pink residual in your water.

The fix is usually simple:-
Simply increase your brine/rinse cycle by 30% and your backwash by 50%

Since it sounds like that's already possibly been done, there are two other alternatives:

1. The distributor pilot o-ring is compromised, or you have a short riser.

2. Water is being used during regeneration (at the exact time your system is switching between piston positions) and permanganate is being drawn into the domestic water.

If you post your cycle times and water pressure information, we can dig into it further.

Originally Posted by bjsjmc View Post
Recently installed greensand filter system model 2510 (fleck?) with 3200 timer successfully removed the sulfur smell from well water in an accessory structure on my property. However, after each backwash cycle (every 6 days) a purplish color is in the toilet bowl after one flush. It takes seven flushes of this low-flush toilet to clear the water (the color is the dye in the manganese I think). The installer has been out twice, adjusting the quick rinse cycle time. Any thoughts about what's going on or how to remedy? thanks... a reluctant do-it-yourselfer.
 
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Old 04-02-08, 09:51 AM
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Update

Thanks for the info, greg...sorry for the delay in getting back (this do-it-yourselfer needed assistance in opening the box to count the pins!)
Backwash time 20 min, brine&rinse 70 min, rapid rinse/refill 30 min. Water is not being used during regeneration, installer says distributor pilot O-ring okay, no short riser, and water pressure more than adequate.
Today the brine/rinse was reduced to 60 min and the floater (?) replaced in the container that has the potassium permanganate in it (just in case it was bad).
Do you still suggest increasing the backwash and brine/rinse times? The brine/rinse time was reduced I'm told to bring less of the potassium permanganate into the tank. I should know in a couple of days if the adjustment today worked.
 
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Old 04-04-08, 09:06 AM
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Sigh

Well, I still have the purplish/pinkish color after the backwash cycle. It always takes the same number of toilet flushes til it's clear again. Though my water was tested and the greensand filter solution recommended, I'm beginning to wonder if there is not something unusual about my situation that is being overlooked. Sigh. At least, this process reenforces my belief that I should never consider doing-it-myself...everything (no matter how small) takes a lot of time, knowledge and experience. This web site is great tho and thanks again for your help!
 
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Old 04-04-08, 02:07 PM
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Permanganate vat

Can you tell us about the container the permanganate is stored in? I have seen some real hack jobs where a "technician" used a 35 gallon brine vat from a water softener and simply punched holes in the permanganate containers and dropped them in to the purple mess in the vat. A correct system should have either a sealed permanganate storage system (it has @ 12 screws holding it together) that the customer can not access easily OR a small vat that looks like a little brine vat @ 16 inches tall and 12 inches across with an easily removed lid (maybe 3 or 4 screws or no screws at all). The sealed type should not be causing you a problem so if you have one of these, look at another part of the system for the problem, like a restricted drain line. The vat type may be filling too high due to a bad or mis-adjusted float, therefore so much of the permanganate is being drawn in that there is not enough time for it to rinse out. Really, the permanganate is drawn in during the first 10 minutes or so during the brine / slow rinse and the other 60 minutes is spent slowly rinsing it through the bed. This increases efficiency of the permanganate regeneration of the green sand. That is why the brine / slow rinse should be set back to the longer original setting.

You mentioned a toilet. Out on a limb here, but does that toilet have a slow leak? If the ring seals on the head of the greensand filter are going bad, some permanganate may get drawn out of the filter into the line that feeds the toilet beacause it is running (slowly). That stuff spreads like wildfire, and the smallest amount getting through will take several flushes to clear out.

Also, please be careful with that permanganate. It tends to react violently with organic compounds like anti-freeze, latex paint, oil, and stuff like that. It can cause a fire.
 
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Old 04-04-08, 09:47 PM
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Arrow Cycle time adjustments...

DECREASING brine/rinse is the worst thing you could do right now. If your installer is making that suggestion, it makes me question his/her technical abilities. - You might want a second opinion from someone local who is more qualified.
Consult wqa.org for a local certified water specialist.

Let's get back to basics here:

If your pressure is 40-60psi, then try the following programming profile:-

Backwash 10 minutes
Brine/Rinse 90 minutes
Rapid Rinse 20 minutes
Tank Fill 8 minutes

Manually initiate a regeneration cycle and then see if you have permangante residual in the water. - Post the results & we'll take it from there.

If your pressure is LOWER than 40 psi, then further programming adjustments need to be made, as well as configuring the injection system for the influent pressure.

What is the maximum flow rate that your well is capable of delivering ?

How much iron and H2S is in the water ?



Originally Posted by bjsjmc View Post
Well, I still have the purplish/pinkish color after the backwash cycle. It always takes the same number of toilet flushes til it's clear again. Though my water was tested and the greensand filter solution recommended, I'm beginning to wonder if there is not something unusual about my situation that is being overlooked. Sigh. At least, this process reenforces my belief that I should never consider doing-it-myself...everything (no matter how small) takes a lot of time, knowledge and experience. This web site is great tho and thanks again for your help!
 
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Old 04-11-08, 12:03 PM
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Post More Info

Today the installer replaced the control valve on top of the unit (the whole thing), ran a quick cycle to verify the unit is working and set it to regenerate tonight.

Current settings:
20 min backwash (10 pins)
92 min brine/rinse (46 pins)
20 min rapid rinse (10 pins)
4 min refill (2 pins)
2 pins to turn off

Results of earlier water testing:
ph 8
hardness 13
iron 1
sulfur 2 ppm
TDS 155

Well and Pressure tank:
15 gal/min from well and 9 gal/min effective
40-60 psi on pressure tank (gauge read 45 when I looked)

The permanganate container (blue) is about 16"h, 10" in diameter with an easily removed lid (black). A 4" diameter white thing is inside (the float); the water level was about 3/8" above the pad today before any other changes. The float was replaced/lowered 1/4" during the previous repair attempt. The installer says he maybe messed up reducing the brine/rinse time. His concern was whether the fact that so little water is used in this accessory building (it is separate from my residence) might be having an effect. The structure has one toilet, two sinks only.

The plastic-looking drain line from the top of the filter tank to the drainage pipe going outside the structure to the septic is about 6 feet long and has been checked for blockage (none). I don't think the toilet is running slowly but I'm not quite sure how to verify (it was newly installed last year when structure was built)...I believe the purple water comes out the faucets too and will verify this tomorrow.

After the installer left, I had purple water...I will see if I have it after the cycle tonight (checking the faucets too). Needless to say, I am concerned that I still have the problem. Also, when the unit was installed in Jan, it was several weeks before I noticed the purple water. In any event, the installer and the supplier (whom I spoke to today for the first time) seem to want to get this resolved (the installer has a very good business reputation in my area). Thank goodness for that...if only they will be able to. Neither is a member of the wqa though the supplier says he's taught classes for the wqa.

Thanks. I know more than I ever wanted to about my water situation...and yet, I know nothing...well, except that my water is purple...and that I should not go into this busi ness!
 
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Old 04-12-08, 10:46 PM
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That 92 minute brine / rinse cycle should do the trick. It should give plenty of time for the permanganate to rinse out. You most likely had purple water right after the guy ran a quick rinse because he was making sure it drew solution but didn't hang around for a couple hours to check the whole cycle.
 
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Old 04-13-08, 09:20 AM
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Post Will Try the Slow Leak Hypothesis

Not surprisingly, I STILL have purple water after the backwash cycle...when I turn on the faucet.

Greg mentioned using water during regeneration and I thought he meant running the faucet or flushing the toilet (this is not the case but maybe he meant a leak).
Cleanwaterman mentioned that a slow leak might be a problem if the ring seals on the filter head were going bad.
The supplier, a master plumber, mentioned a leak too and he said it may not be an obvious leak.
When the installer was out, I asked him if I might have a toilet leak and did he want to see the toilet. He looked at the gauge on the pressure tank and said it was steady so he didn't expect a leak (he did not look at the toilet).
Later I examined my toilet closely (not knowing really what to look for) and noticed two discolored lines down the back of the bowl (I thought maybe I needed to clean the toilet...it did not appear to be wet where the lines were)...but on the off chance that this might be a slow leak, I have a call into a plumber. I don't know what else to do. I will inform the installer on Monday of the status.
 
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Old 04-15-08, 09:16 PM
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Wow, this is a stumper! If the backwash line is not kinked and you have a new valve head, has anyone checked the backwash flow control? Has anyone checked to make sure the well is keeping pace with the demand of backwash through the entire cycle? Is your pressure ok in the rest of the house?
 
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Old 04-30-08, 10:35 AM
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Last Straw

No leaks, water pressure fine. Pink water still. Today, the pressure tank was set from 40-60 to 50-70 in a last ditch effort to remedy the problem. The system will be likely be removed if that doesn't work. No one knows what else to do.

Most disturbing: The supplier AND an independent plumber (who quit working with these types of systems) have said that they have seen systems installed where the pink water NEVER went away. I ask you what kind of manufacturer sells a product like that?

The guys today think low water usage may be responsible but it doesn't make sense to me...shouldn't the rinse get rid of the potassium permanganate no matter what?

Anyhow, what kind of system might work for my situation. It is not easy to get a WQA person in my area.
 
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Old 04-30-08, 11:14 PM
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I agree with that plumber. I never install these systems. My biggest beef is the fact that pot perm is highly reactive and can cause a fire when mixed with an organic compound (i.e. latex paint, antifreeze, oil, newspaper, old leaves). I do get stuck working on them and I never have this pink water problem persist after I start working on it. Just one more guess - does another filter or a water softener come after this filter and does it backwash at the same time, or are drain lines from two backwashing units teed together and somehow allowing rinsed out permanganate to enter a second filter?

I prefer aeration, venting, filtration systems as long as the odor is not too high.

http://cleanwaterman.blogspot.com/
 
 

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