Iron filtration question
Hooray!! I now have "sufficient priveleges" to post a new thread! I need some advice on a filter system, and wanted to ask everyone's thoughts. Here is my information.
I have a well that produces 5gpm. It was originally set up as a "standard" well system (well pump to pressure tank to softener to house), and I had a Kinetico softener installed. Everything was fine, but I had very poor pressure and flow. So, I removed the pressure tank, added a 550 gallon cistern and Davey booster pump in my basement (well pump to cistern with level control to booster pump to softener to house). Now I have great pressure and flow, but have developed a bit of a rust problem. Clear water coming in, but much red staining in the bottom of the cistern, which carries through to discolored water and staining in the fixtures of the house. So, I know I need additional filtration ahead of the softener. I like the Big Blue type filters rather than a backwashing filter because I don't want to use that much more water backwashing filters. I already have a slow-producing well, and don't want to place extra load on my septic system.
I had my water tested, and the results are shown here:
- Turbidity - 8 ntu
- Ph - 7.6
- Iron - 0.68 ppm
- TDS - 540 ppm
- Hardness - 18-20 grains
After the softener
- Turbidity - 0 ntu
- Ph - 7.6
- Iron - 0.60 ppm
- TDS - 547 ppm
- Hardness - <1 grain
Softener seems to be doing its job, but won't touch the iron that has precipitated out.
After much research on many sites, I was thinking of this as a system:
- Pentek 160168 BBFS-222 triple housing
- Liquatec SDF-45-2005 Sediment filter
- Pentek Radial Flow Iron Reduction Filter 155263
- KX Matrikx +5 02.425-125-20 Carbon Block Filter
Does this make sense, and do you have any feel for how long the filters would last before requiring changeout given my water information?
Thanks in advance for reading this and giving me your thoughts.
IMO the cistern was a bad idea, unless you actually ran out of water.
I also think the disposable cartridge type filters are a bad idea. You are already questioning the frequency (and cost in time and money) of their replacement.
A correctly sized automatically backwashed turbidity filter with a Clack WS-1 control valve can't be beat.
I take it you mean the 5 gpm was the well's recovery rate, how deep is the well? What is the static water level. How deep is the pump? What diameter is the well? What pump, hp and gpm rating, is in the well? I.E. a 200' deep 6" well with a water level of say 50' and the pump at 180' with a 5 gpm recovery rate has 130' of water at 1.47 gals/ft of water. The pump should be a 1/2 to 3/4 hp 10-13 gpm. And that would produce more water than a 3 bathroom house with 4 people could use.
If the pressure was low, you should have found the problem or simply set the system air and water pressure higher; like to 39-38 psi air in the pressure tank and the pressure switch to 40/60 psi. And now you should clean the rust out of the cistern and disinfect it periodically.
If the well is a 3-4" sand point with a jet pump, that's different, but still, disposable cartridge filters will not make you happy.
Thanks for the reply. I don't have all of the specifics on the well. When I say 5 gpm well, perhaps as you say, it is 5 gpm recovery. The well was already drilled when we bought the property, and our contractor had the well driller install the pump, plumbing, etc up to and including the pressure tank. From conversations with him, all I can say is that he was told not to go above a 5 gpm pump. Now, if I hold a bucket under the incoming line into the cistern, it will fill at a 5 gpm rate. So, no, we didn't have enough water for a 3 bathroom house. We never actually ran out of water, but we ran down to a trickle from the shower head if the dishwasher, clothes washer, or 2nd shower/bath was running at the same time. The proposal from the well driller to add a 2nd 120 gal pressure tank and give us only 60 gallons more stored water (for around $1600) just didn't make sense.
We live in an area that doesn't have the most plentiful ground water supply. I've heard that one neighbor three homes down actually has a cistern and has water delivered because they couldn't find a good well. It is this concern that was really driving me toward cartridge filters vs. "wasting" more water through backwashing a sediment filter. It is easy to understand the cost of the cartridge system if I knew how often to change the cartridges. It isn't as easy for me to establish the cost of a backwashing filter when trying to capture the cost of the backwash water, power, and frequency of backwashing. I headed down the path of cartridges after speaking to another water professional (who sells all types of backwashing filters), who saw my water test results and said that the numbers weren't bad enough to drive me into a backwashing filter (birm or Filox).
For the sake of comparison, our household is:
- 3 1/2 bath
- Four people
- One two-headed shower (both heads used maybe 25% of the time)
- No large animal water usage
- Flower bed irrigation (through soaker hose) for 8 minutes per day.
What model Kinetico do you have? If you are getting light amount of precipitated (ferric) iron coming through the softener, which won't take out that type of iron, then a sediment filter will work very well. I would get a 4.5" x 10" pleated filter at about 20 microns.
These can be washed out (sanitized) and used again and again. This will require a little babysitting in monitoring the filters and changing them out if that is not a problem. Cost is minimal compared to a backwashing filter.
I would avoid using a carbon filter on well water as an initial treatment.
Put a pressure gauge before and after the filter and watch for about a 15 psi drop while water is running through. This may indicate when to change the filter.
Did you get an RO, as well?
Andy Christensen, CWS-II
Thanks for your response as well. Our softener is a Kinetico Mach Series, but I can't remember a specific model number. We do have a Kinetico RO (3 canister) system for the refrigerator and sink drinking water taps. Very pleased with the Kinetico softener, just not so much with the iron that is passing through.
Thanks for the suggestions.
Yes the 5 gpm well is the recovery rate of the well, that's all it can be. But you always have storage capacity in a well. The water level isn't at the inlet to the pump so you can pump more than just the same gpm as the recovery rate. If you have a 4" or larger diameter well you have a lot more water than 5 gpm. As to your low flow in the house, flow is dictated by the pressure and you could have increased the pressure very easily.
Originally Posted by Todd D
Since you are only getting 5 gpm out of an open pipe at the cistern, you have an undersized pump because even a 5 gpm pump should be delivering more than 5 gpm open discharge.
You also could have replaced the wet end of the pump, that's that part of a pump that is rated in gpm. You select which one based on the peak demand gpm the house requires at the psi you want to run the system at, THEN you select the hp to do the job. You DO NOT size a pump based on the recovery rate gpm of the well.
Now you have a rust problem in the 550 gallon cistern... depending on the iron content of the water it can create a lot of rust on the bottom. A correctly sized turbidity filter, that is not an iron filter as Birm or Filox is, would backwash with 50-75 gals every 6-8 days. You have more than enough water for that.
Why would anyone consider that water as "wasted" when we don't consider other water we use to improve our lives as wasted; like taking an extra shower, or a bubble bath, or watering lawn or plants that can't survive in the environment they are planted in unless they are watered constantly, washing vehicles, etc. etc. etc.?
Using disposable cartridges, even the largest, a 4.5" x 20", or a reusable bag filter, may require very frequent replacement or cleaning but no one can say how frequently, only experience will tell you. And once you replace a 4.5" x 10 or 20" cartridge, you very possibly won't want to do it again anytime soon.
You should have a filter in your well storage tank that filters out the rust and sediment. I have a well and there is a lot of rust and sediment in our 5000 gallon storage tank. However it does not cause a problem because we have the correct filter inside our storage tank. The water is then fed in to a whole house filter and then fed to a water softener. Any iron left in the water, is taken out by our softener no problem. A high quality softening resin will take out up to 10ppm of iron. You will have to use a res cure automatic despenser in your brine tank to clean your resin effectively.
Last edited by chaseme5; 12-16-2008 at 06:26 AM.
What type of filter is installed in a cistern?
How frequently do yu clean or replace it?
You mean correct type of resin, not quality of resin. The best resin for high iron is SST-60 because it is not near as prone to iron fouling as regular or fine mesh resins; the only other types there are. That's due to its shallow shell technology (SST) bead construction.
IMO the best and least expensive resin cleaner is Iron Out mixed in a gallon+ of warmish water poured into the water in the brine and then do a manual regeneration once a month.
The company that drilled our well installs a new filter in our cistern every 2 years. The filters cost is about $150 without labor to install it. I do not know where to buy them or I would replace it myself. It is a big drum sized filter. Used to remove sediment, sand, rust, leafs, ect. And these types of filters work really good. There is no sign of sediment in our water.
Look at this website, the filter looks similar to this.
All I know about resins are that the more expensive ones use a new technology that prevents the resin from fouling prematurely. And this new resin takes less salt to recharge.
I also know that there are resins for picticular problems. Like high iron. I was told the there are economy resins and high performace resins.
Last edited by chaseme5; 12-20-2008 at 05:05 PM.
You would be money ahead if you didn't have the filter and used a backwashed filter, after your cistern pump adn pressure tank, to filter the water as you used water from the cistern. Your cistern would get as dirty from rust if you have iron in the well water and you wouldn't have this filter's purchase price and then the replacement expense every few years.
SST-60 is what you're talking about. And yes, salesmen will claim lower salt use and fewer gallons of water to regenerate it.... YMMV substantially.
There are only two other types of resin, maybe you forgot that I mentioned them before... regular and fine mesh. Economy means price and yes, you can pay more or less for the same volume and type of resin from one dealer to another.
That is the same filter we use on out pond systems. Do you know the micron rating? It is good because it draws water from about 18" from the surface.
Originally Posted by chaseme5
We have a lot of cisterns in my area. 20% are rain catchment; all others are delivered or delivered/rain with an optional switch. Cisterns have some advantages but often need special consideration due to what happens to water when sitting for periods of time in atmospheric/ambient conditions.
Problems can occur with foreign matter entering the water, including macro- and micro-organisms.
I can tell you which kinetico you have by measuring the tanks. I suppose the RO has a black tank, right? That one is water powered. It should provide twice the water with no pressure loss. How old is your system?
Andy Christensen, CWS-II
That was an example of a similar filter that is used on our storage tank. I do not have information on the exact filter because a company services the tank every 2 years. They supply the filter. I believe the filter has an 20 micron rating on the outside and a 8 micron rating on the inside. The filter alone cost $150 that's all I can tell you. We also have an ozone generator O3 to take care of micro-organisms.
Last edited by chaseme5; 12-22-2008 at 03:29 AM.
Well, clearly, you are taking your water seriously. Most of our pond filter are at teh 50 micron rating.
What kind of 03 system do you have? How is it set up? There are many good features about ozone production and use.
I still say that a $650 automatically backwashed layered multimedia filter is a better choice if for now other reason than price. Especially for a well cistern with no leaves sticks etc..
I understand your relunctance to go with a backwashing filter.
They require an amount of water vloume and flow rate to be adequate. Many of my customers that are on, or were on cisterns, and their biggest complaint was the need to monitor water levels and not get stuck without sufficient quantity.
Some are rainwater catchments and some are truck-delivered services, but all customers have a second-sense about every drop that is being drawn from the cistern, something most well customers never need to appreciate.
Some filters are washable and reusable. Are you able to change the filter yourself? If so, yo could save some money on that portion of your water treatment needs.
Andy Christensen, CWS-II
Last edited by Andy CWS; 12-24-2008 at 08:21 AM.
Andy, maybe this will help you, Chaseme5 said: The company that drilled our well ...
My well is used for irragation, horses, and for the house. filters and ozone is used to make the water safe to drink. Without a softener the untreated water damages the pumbing and fixtures in the house. Pipes will develop pin hole leaks, water heaters fail, ect. The water tastes terrible so I have to run it through a RO. My ozone generator is a TWTS-101.
Last edited by chaseme5; 12-25-2008 at 03:48 PM.