Calibrating New Greensand Water System


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Old 07-14-10, 05:07 AM
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Calibrating New Greensand Water System

We purchased a house where the well water was shocked into potable state and a bad UV install was done for coliform.

Sure enough a water test after we were in the house showed that the iron and manganese had not magically disappeared, nor was the UV system working effectively.

Circulating the water test to several online suppliers led to a recommended system

pre (sediment) filter-->1.5 cu ft Greensand (Fleck 2510 head)-->post filter (.5 micron)-->Sterilight UV-->house water

I installed this combination and had everything working. Instant improvement in water taste/odor (we did not have much sulphur smell).

Felt like a hero!

I then had to set up the brine tank (it looks like a Clack--small plastic, 2 screws in lid, enclosed adjustable float). Here I started to have problems. A test cycle had left the water too high above the grid (probably 6" of water), so I adjusted the float down--the Clack specs suggested (?)2 3/4" for 1 cu. ft--but because it sits in heated space, I assumed that it should be set about the same for the 1.5 cu ft. (I should add that I had line leaks since I had not assembled the little compression fittings correctly, so in retrospect this may not have been an accurate end state.)

Regrettably, I did not run another test rinse. I then added two 2lb bottles of pot perm, did a manual wash and set the system for a 3 day cycle.

After the first manual wash with the brine tank in operation, my rejuvenated water had picked up an odor--it seemed familiar, & then it struck me that it smelled like saltpeter--an unforgettable smell that I remember from teenage experiments with explosives.

After the second wash the odor was even more noticeable. It seems present on both hot and cold sides, but seems to dissipate somewhat when you check the taps that are the farthest away...I checked the brine tank, & there is essentially no water present above the grid--just a little pile of caked permanganate. There is no purple staining at the tap, however--but all the water is going through a .5 micron spun poly filter.

The install instructions recommended a shock treatment with bleach--and leaving the chlorine treated water in all the lines before flushing & I did not do this, since I worried about its effect on the septic tank.

I'd also planned to substitute a Carbon filter for post treatment, but I wanted to make sure that the system was working as it should & not just mask odors that could be a result of a faulty setup.

Lot of questions, but the first is, how do I know if the float level in the brine tank is set right? Should I see water above the grid as well as some undissolved permanganate?

Dean
 

Last edited by paredown; 07-14-10 at 05:13 AM. Reason: add detail
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Old 07-14-10, 07:40 AM
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No good dealers in your area?
 
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Old 07-14-10, 09:10 AM
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The dealer selling you the equipment should provide setup instructions so my first suggestion is to ask your questions of the selling dealer.

That said I suspect you created your own problem by changing the adjustment of the safety valve. The safety valve is there to prevent the tank from overflowing--not to regulate the refill of the regenerant tank. The setting of the safety valve is not a function of the amount of media--it is a function of the height of the overflow on the regenerant tank--the valve is supposed to close if the level of fluid in the regenerant tank rises above a "normal" level. The amount of water put into the regenerant tank is controlled by the control valve and the settings are part of the programming process for the control valve. However if the safety valve is improperly adjusted it will cut off the refill prematurely and then you get inadequate regeneration.
 
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Old 07-14-10, 07:35 PM
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Thanks for the responses. No dealer close by, and the system was purchased online. The dealer does provide written instructions, & it was he who told me on the phone to adjust the float so that there would be 3/4" of water above the grid--and this was in his written instructions as well.

Not trying to be argumentative, but if the amount of liquid in which the permanganate is dissolved is indifferent & injection controlled by the head (and the float merely serves to prevent overflow), why does Clack show different settings/models rated on the oz. perm/gals of solution? The only significant difference between a 2 oz system and a 4 oz system is that the first has a 1/2" shorter riser pipe and the float set lower.

Is the idea just that the system will demand a certain amount (and concentration is more or less just whatever will dissolve given water temps) that needs to be present in the tank--so it can't be undersized?

Tomorrow I'll take it apart again and reset the float where it was originally (lower than the 4" that Clack suggests for the "4 oz" system but higher than it is now) before the next regen & see how that works.
 
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Old 07-15-10, 02:54 AM
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So are you saying that you have water quality problems with the float adjusted to give 3/4" of water above the grid which is the dealer recommendation?

What does your dealer say about that?

I ask because the problem you are having seems to be the result of inadequate regeneration. That could be because the dose of potassium permanganate is insufficient for the quantity of media or because you are not regenerating frequently enough. New media performance will rapidly degrade if not regenerated with the correct dose and/or frequently enough.

The description I provided was for brining with a softener. With potassium permanganate the safety float is also used to control dosing. Sorry if I mislead you.

Dosing is a function of the quantity of media--1.5 cubic foot of media requires a dose that is 1.5 times the dose for 1 cubic foot.

The quantity of solution to achieve the desired dose rate is very dependent on the temperature of the solution.

You may have to do a bit of experimentation with the dose and with the frequency of regeneration to get satisfactory performance. If the temperature of the room where the solution tank is located is not stable that will cause continuing problems because the amount of potassium permanganate that dissolves per unit of water varies sharply with temperature.
 
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Old 07-15-10, 06:25 AM
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Originally Posted by Bob999
The dealer selling you the equipment should provide setup instructions so my first suggestion is to ask your questions of the selling dealer.

That said I suspect you created your own problem by changing the adjustment of the safety valve. The safety valve is there to prevent the tank from overflowing--not to regulate the refill of the regenerant tank. The setting of the safety valve is not a function of the amount of media--it is a function of the height of the overflow on the regenerant tank--the valve is supposed to close if the level of fluid in the regenerant tank rises above a "normal" level. The amount of water put into the regenerant tank is controlled by the control valve and the settings are part of the programming process for the control valve. However if the safety valve is improperly adjusted it will cut off the refill prematurely and then you get inadequate regeneration.
I have not dealt with Greensand units very much, but I was taught the the float does control the amount of KMNO4 a unit uses. The more media, the higher the float. For 2oz the float must be set at 2 1/2", for 4oz it's set at 4" and 6oz is set at 5 5/8". I normal buy a 1 cu ft and use 4oz per regen.
 
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Old 07-19-10, 06:11 PM
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Thanks again--I did reset the float level and it now seems to leave about 3/4" above the grid after the cycle runs.

The odor is still present, but not as bad as before.

The whole setup sits in the furnace/water tank room, so it is pretty warm all the time, which ought to help keep a fairly consistent solution.

Currently I have the cycle set to regen every three days (it's a two person household, so not a very high water usage--although I don't have a meter to actually track volume).

So my next three choices would be:

1. Move the float still higher--to give a 6oz dose for the 1.5 cu ft of media;

2. move to an every 2nd day regen. My question here would be--is the frequency dependent on water volume, or amount of iron/manganese you are trying to remove?

3. Change my post filter to a carbon monoblock to remove residual odor. (I plan to do this anyway, but want to be sure I've got the basic system working as well as possible first.)

Ideas which I should try first?

(Even though I have some odor, the water is greatly improved (minimal staining, nice slippery feel in the shower etc.))
 

Last edited by paredown; 07-19-10 at 06:14 PM. Reason: Add detail
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Old 07-20-10, 06:38 AM
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If the odor is present after regeneration--that is it doesn't gradually appear and get worse between regenerations--I recommend increasing the dose to see if that resolves the issue. If the odor gradually appears and gets worse I recommend increasing the frequency of regeneration.

Frequency of regeneration is a function of total amount of iron/manganese/sulfer removed and that is a function of the level of those items in your water and number of gallons used.
 
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Old 08-12-10, 05:38 PM
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what are the water quality test results? perhaps this will give some insight as to the proper programming & treatment you require.
 
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Old 08-12-10, 07:07 PM
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Greensand

Most people selling greensand systems have no clue about water treatment. KMNO4 is highly oxidative and dangerous. That being said, most folks installing greensand systems do not account for the high density (weight) of the media and do not check to make sure the well pump can provide sufficient flow rate to lift and rinse the bed. Instead of designing systems tailored to the flow rate of the well pump, they design systems tailored to what they believe is the maximum flow rate of the home, with catastrophic results. You may have a system that is too large for your well pump to adequately rinse, or your backwash flow restrictor is too small. Sorry, but most greensand systems fail.
 
 

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