Lots of Iron in my cisterns. Any advice?

[Eric70]

Hello all. I was wanting to see if anyone had any ideas on an issue I’m having. I have a 800’ well, and had a water analysis recently done. I knew the well had high levels of Iron, and the analysis reported 1.183 mg/L. I had an Iron filter installed several months ago which uses Katalox Light (the guy who recommended and installed the filter claims Katalox Light can handle Iron at that level?).

I also had a well production test done a couple months ago, and it averaged producing 0.03 gallons per minute (roughly 50 gallons per day!). With that in mind, and having had many issues running my well dry, I had (2) 175-gallon cistern tanks installed in my mechanical room. What I’m having issues with is that the cisterns are completely covered on the inside with Iron. I’ve had to run the cisterns as empty as I can (there’s still about 6” of water in each) and vacuum the water out to suck up a good 2” of Iron that’s accumulated on the bottom. The sides of the cisterns are also stained with a dark Iron color.

So far, even with the water in the cisterns being a dark Iron color, the Iron filter seems to be filtering out any noticeable Iron smell or taste. I run a backwash every 3-5 days (the backwash typically lasts around 9 minutes, and the rapid rinse about 4 minutes) so hopefully that is adequate to clean it out?

My question is whether there is a filter that could be installed either in the cisterns, or prior to the cisterns where the well water pipe comes into the home? When I do a sample of the well water, it doesn’t have any noticeable discoloration or odor, yet when it becomes oxidized in the cisterns the Iron residue starts to form (at least that’s how I understand it?). I’m getting concerned that the Iron “sludge” will continue to accumulate, and having to vacuum it out every week or so is getting pretty old!

If you all have any insight or suggestions, I’d appreciate it!

 

[Reach4]

KL filter is before or after the cisterns? I suspect after. The air is oxidizing much of the iron, and the ferric iron settles.

There are conical bottom tanks that could let you dump the sludge from the bottom more easily.

There is probably something that can let you pick up the sludge without emptying the tanks first. I am thinking a pump cycling the water through some kind of cleanable filter.

I am not a pro.

 

[Sponsor]

 

[Eric70]

KL filter is before or after the cisterns? I suspect after. The air is oxidizing much of the iron, and the ferric iron settles.

There are conical bottom tanks that could let you dump the sludge from the bottom more easily.

There is probably something that can let you pick up the sludge without emptying the tanks first. I am thinking a pump cycling the water through some kind of cleanable filter.

I am not a pro.

Yes, the KL Filter is after the cisterns and pressure tank. The cisterns each have an opening about 3” from the bottom where piping is connected to feed into the booster pump and pressure tank. So, the Iron sludge seems to just settle in that bottom 3”. As you said, I was thinking maybe a pump at the bottom of each cistern would help cycle that water/sludge as to avoid it settling?

Is a KL Filter capable of cleaning out heavy Iron residue and not getting clogged up? It seems to be doing a decent job so far? I would ask the guy who recommended and installed the filter, yet I’ve unfortunately learned the hard way not to trust a word he says

 

[Reach4]

Yes, the KL Filter is after the cisterns and pressure tank. The cisterns each have an opening about 3” from the bottom where piping is connected to feed into the booster pump and pressure tank. So, the Iron sludge seems to just settle in that bottom 3”. As you said, I was thinking maybe a pump at the bottom of each cistern would help cycle that water/sludge as to avoid it settling?

I am not sure what would be best, but a 1/2 HP utility pump might be sufficient. Those suck from the bottom. A sump pump is similar and pumps from near the bottom. Then route the output through a filter (I am not sure what would be best for that) and that water goes back into the tank.

A sump pump pumps lots of volume but cannot develop much pressure.

Is a KL Filter capable of cleaning out heavy Iron residue and not getting clogged up? It seems to be doing a decent job so far? I would ask the guy who recommended and installed the filter, yet I’ve unfortunately learned the hard way not to trust a word he says

I am not sure. You have an unusual situation.

 

[Eric70]

I am not sure what would be best, but a 1/2 HP utility pump might be sufficient. Those suck from the bottom. A sump pump is similar and pumps from near the bottom. Then route the output through a filter (I am not sure what would be best for that) and that water goes back into the tank.

A sump pump pumps lots of volume but cannot develop much pressure.


I am not sure. You have an unusual situation.

Thanks! I’ll have to do some research to see if there’s a pump that I can attach a hose to that can suck that iron sludge up to the top of the cistern, and then down the drain close by? (the cisterns are about 5’ tall, so the pump would need to have pretty decent pressure). That would at least be easier than vacuuming (and dumping outside) all the sludge.

Hopefully I can find a permanent solution to the Iron developing in the cisterns, or at least be confident that the KL Filter can continue to handle it.

At the time I had the Iron filter installed, I also had a pellet drop chlorinator put on top of the well head. However, when my well pump got stuck, and I had a new pump installed, two Well Drilling Companies told me they didn’t recommend pellet drop chlorinators (they thought the pellets could calcify and actually do harm to the pump??). I would think the chlorinator would help combat the Iron in the well itself, yet I don’t want to do any more damage than what was already done.

 

[Reach4]

Thanks! I’ll have to do some research to see if there’s a pump that I can attach a hose to that can suck that iron sludge up to the top of the cistern, and then down the drain close by? (the cisterns are about 5’ tall, so the pump would need to have pretty decent pressure). That would at least be easier than vacuuming (and dumping outside) all the sludge.

The pumps that can do that are pretty common. I think you would want to circulate a bleach solution in a 5 gallon bucket before putting the pump into your tank.

A solution that lets you re-use the water after filtering out the rust sounds more useful, since your well only produces about 50 gallons per day. That is where you might need a pump that can produce more pressure than a common utility pump, depending on the backpressure of the filter. I don't know what filter size is the right thing to filter out your sludge.

I could even see you pumping up to a container that slowly drips filtered water back into the cistern.

 

[Reach4]

OK... here is another idea that may or may not be a good idea. You run a hose from the output of your KL tank back to your cistern. Maybe have the water go to the bottom of the tanks with a piece of pvc pipe. The water coming out of the pipe puts the sediment into suspension, and it gets sucked up by your pressure pump. The water passes thru the KL tank, gets stripped of its solids, and returned.

Maybe have the flow big enough that the pressure tank does not fill up during this process, because the water pressure at the pressure tank is below the precharge pressure. When done, backwash the KL tank.

I guess the sludge goes into your septic tank. Don't forget to get that thing pumped often enough.

There is likely a flaw in this idea.

 

[Eric70]

OK... here is another idea that may or may not be a good idea. You run a hose from the output of your KL tank back to your cistern. Maybe have the water go to the bottom of the tanks with a piece of pvc pipe. The water coming out of the pipe puts the sediment into suspension, and it gets sucked up by your pressure pump. The water passes thru the KL tank, gets stripped of its solids, and returned.

Maybe have the flow big enough that the pressure tank does not fill up during this process, because the water pressure at the pressure tank is below the precharge pressure. When done, backwash the KL tank.

I guess the sludge goes into your septic tank. Don't forget to get that thing pumped often enough.

There is likely a flaw in this idea.

Interesting idea! I’m going to get in touch with the guy who installed the cisterns and new pressure tank, and run your idea by him (or see if he has any other suggestions on a permanent fix?)

I did some quick research online regarding the utility pump idea as just a means of getting the sludge out of the bottom. Found a submersible 1/4HP pump with a hose attachment. Not sure if something like that could suck that sludge up 5’, but it may be worth a try?

I’m also trying to see if there’s a powder/substance or something that I can periodically add to the tanks to keep the Iron from forming? I tried bleach and vinegar, but that didn’t work. Super Iron Out works miracles to get rid of Iron in toilet tanks and bowls, yet it’s pretty toxic, unfortunately.

 

[Boycedrilling]

You’ve discontinued using the chlorine pellet injector? The chlorine pellets would have been oxidizing the clear water ferrous iron and depositing that sludge you’re getting in your cisterns in your well. Do you want the crud in your well, or in the cistern, where you can clean it out easily?

 

[Drick]

I have a setup sorta similar to yours. First, the order you have your equipment installed cistern-->pump-->filter is the correct way. If you move the filter(or install a second filter) before the cistern it won't filter out the dissolved iron. Water filters cannot remove dissolved iron. They can only remove it after it becomes a solid and that happens after the water has been in contact with the air. (That being the air in your cistern). Second, you are working too hard keeping those tanks clean. Yes you are helping out the KL filter by removing the water with the highest concentration of iron, but at 50 gallons a day your water usage is really low. I'd probably just let the filter do its job.

If you want to help the filter out a bit you could do the following; T off after the pump. Add a foot (or two or 3) of pipe and then a shutoff. The run a pipe outside your house (or to the septic but you would need an air gap for safety). The pipe size should match the pipe size for your pump (Don't reduce it). Once a week open the valve for a minute. The unrestricted flow rate will help to remove some of the iron from the cistern. This is how my mine is set up except that it is pressurized and a solid color. It is also not accessible from the top so I have no idea what it looks like on the inside. I can tell you its worked for over 10 years and I'v only changed my filter medium once during that time.

Edit: Just saw Boyce's post about the chlorine pellet injector. As long as there is an air gap at the top of your cistern you don't need to be doing that. Your cistern will oxidize the water and convert the iron to a solid at that stage.

 

[Eric70]

You’ve discontinued using the chlorine pellet injector? The chlorine pellets would have been oxidizing the clear water ferrous iron and depositing that sludge you’re getting in your cisterns in your well. Do you want the crud in your well, or in the cistern, where you can clean it out easily?

I’m not sure who to believe about the chlorinator? The guy who installed the Iron filter and chlorinator did so in order to attack the Iron in the well, and then the KL Filter would do its job inside the home. However, the two Well Drillers didn’t like it due to the possibility of the pellets calcifying and possibly damaging the pump.

After recently paying a small fortune to replace my “stuck” pump 800’ deep, as well as check valves, etc, I want to do everything I can to keep my well healthy and hopefully never open up the cap again

 

[Eric70]

I have a setup sorta similar to yours. First, the order you have your equipment installed cistern-->pump-->filter is the correct way. If you move the filter(or install a second filter) before the cistern it won't filter out the dissolved iron. Water filters cannot remove dissolved iron. They can only remove it after it becomes a solid and that happens after the water has been in contact with the air. (That being the air in your cistern). Second, you are working too hard keeping those tanks clean. Yes you are helping out the KL filter by removing the water with the highest concentration of iron, but at 50 gallons a day your water usage is really low. I'd probably just let the filter do its job.

If you want to help the filter out a bit you could do the following; T off after the pump. Add a foot (or two or 3) of pipe and then a shutoff. The run a pipe outside your house (or to the septic but you would need an air gap for safety). The pipe size should match the pipe size for your pump (Don't reduce it). Once a week open the valve for a minute. The unrestricted flow rate will help to remove some of the iron from the cistern. This is how my mine is set up except that it is pressurized and a solid color. It is also not accessible from the top so I have no idea what it looks like on the inside. I can tell you its worked for over 10 years and I'v only changed my filter medium once during that time.

Edit: Just saw Boyce's post about the chlorine pellet injector. As long as there is an air gap at the top of your cistern you don't need to be doing that. Your cistern will oxidize the water and convert the iron to a solid at that stage.

Thanks! I’m trying to get educated on all this, so pardon many of my stupid questions. The guy who installed the KL Filter and chlorinator said that chlorine is needed to oxidize the Iron, and then the KL Filter traps that Iron in the media and it’s periodically backwashed out. Yet my understanding (and what you just said) is that air, versus chlorine, oxidizes the Iron and makes it solid. The guy said that without chlorine the KL System wouldn’t be able to be effective, but is that really the case? (again, after the nightmare I had with that guy, I never trust a word that comes out of his mouth).

I’m under the impression that chlorine in the well is more of a disinfectant than a means to oxidize?

If it’s not really necessary to remove the “sludge” in the cisterns, and just stop being paranoid about the discolored water, I’m okay with that! I’ve read up on the Katalox Light, and it appears that it’s very capable of handling Iron levels like I have (at least I hope so!).

 

[Boycedrilling]

Chlorine is an oxidizer. Chlorine injection or just air injection will precipitate iron. You have clear water iron. Also called ferrous iron. Oxygen, whether it is from chlorine or air will change the ferrous iron to ferric iron, which is now a solid and can be filtered out.

 

[Eric70]

Chlorine is an oxidizer. Chlorine injection or just air injection will precipitate iron. You have clear water iron. Also called ferrous iron. Oxygen, whether it is from chlorine or air will change the ferrous iron to ferric iron, which is now a solid and can be filtered out.

Thanks. That makes sense. I knew there were two different types of iron, but wasn’t clear on just what oxidizes the ferrous iron. I thought that there may be ample air in the well to oxidize the ferrous into ferric, but when I sample the well water it looks clean and tastes pretty decent (thus the “clear water iron”?). And when it’s allowed to sit in the cisterns it gets enough air to oxidize into the solid ferric form?

I guess my question is...do I really need chlorine (or the pellet chlorinator) since air in the cisterns is oxidizing the iron into a solid form for the KL filter to trap it and backwash it out?

Uggggh...living on a well isn’t turning out to be so easy!

 

[Reach4]

I did some quick research online regarding the utility pump idea as just a means of getting the sludge out of the bottom. Found a submersible 1/4HP pump with a hose attachment. Not sure if something like that could suck that sludge up 5’, but it may be worth a try?

I expect that it could suck up 5 ft. If it were just water being sucked, the only work is raising the water from the water surface over the rim. Because you are sucking some solids with the water, a little more suck is needed. It it is harder to suck off of the bottom when the tank is almost empty.

Utility pumps and sump pumps often publish curves that describe the behavior.

 

[Eric70]

I expect that it could suck up 5 ft. If it were just water being sucked, the only work is raising the water from the water surface over the rim. Because you are sucking some solids with the water, a little more suck is needed. It it is harder to suck off of the bottom when the tank is almost empty.

Utility pumps and sump pumps often publish curves that describe the behavior.

I’ll have to do a bit more research on it, yet this one has a “max head 25 feet” (whatever that means?) and can move up to 1800 gallons per hour. It looks like it can suck down to 1/4” of water off the bottom. However, as you said, whether it can suck that sludge up to the top??

One other question on this issue. With the obvious high amount of iron in my water, and it being noticeably “irony” in color, should I expect to see that discoloration when the iron filter is backwashed? I’ve noticed that during a backwash the water being backwashed down the drain is pretty much clear. I would have assumed that with all the ferric solids being trapped inside the iron filter media that the backwash water would be filled with those solids and discoloration being flushed out?

 

[Drick]

The guy who installed the Iron filter and chlorinator did so in order to attack the Iron in the well, and then the KL Filter would do its job inside the home. However, the two Well Drillers didn’t like it due to the possibility of the pellets calcifying and possibly damaging the pump.

I'm thinking the guy who installed the chlorinator didn't understand that your cistern could precipitate the iron all on its own. My guess is he has probably sold the chlorinator and KL filter before to other homeowners with iron problems and it worked for them so that is what he sold to you. I also tend to side with the well drillers - don't put anything down the well unless you really need to.

when I sample the well water it looks clean and tastes pretty decent (thus the “clear water iron”?). And when it’s allowed to sit in the cisterns it gets enough air to oxidize into the solid ferric form?

It takes about 20 minutes for the iron to oxidize after it comes in contact with the air (or chlorine). Thats why it can look clear at first.

Your water is only partially oxidized by sitting in the cistern. The water really gets oxidized when it falls through the air when your cistern is filling (Your cistern does fill from the top, correct?). What the water sitting in the cistern is providing you with is time for the iron to move from a dissolved state to a solid one. You need 20 minutes from the time the water is oxygenated to the time it reaches the filter. You have much more than that so nothing to worry about there.

One other question on this issue. With the obvious high amount of iron in my water, and it being noticeably “irony” in color, should I expect to see that discoloration when the iron filter is backwashed?

The answer is maybe. When I first installed my filter about 20 seconds into the backwash cycle I could see the iron in the waste water for maybe another 20 seconds if I was watching closely for it. More recently I noticed that I cannot see it anymore. I'm not sure what changed but I know the filter is working.

I guess my question is...do I really need chlorine (or the pellet chlorinator) since air in the cisterns is oxidizing the iron into a solid form for the KL filter to trap it and backwash it out?

I'd say you don't need it and that its probably doing more harm than good in your system. As long as you have an air gap the water is falling though as your cistern fills I would turn off the chlorinator and see what happens. Worse case is you'll have to turn it back on again if the iron gets past your filter.

 

[Reach4]

I did some quick research online regarding the utility pump idea as just a means of getting the sludge out of the bottom. Found a submersible 1/4HP pump with a hose attachment. Not sure if something like that could suck that sludge up 5’, but it may be worth a try?

I’ll have to do a bit more research on it, yet this one has a “max head 25 feet” (whatever that means?) and can move up to 1800 gallons per hour. It looks like it can suck down to 1/4” of water off the bottom. However, as you said, whether it can suck that sludge up to the top??

See https://www.superiorpump.com/products/utility/91250.html and click on the Specifications tab. You will see a graph and a table. It says that pump can lift 25 feet but only with the flow near zero. It can pump 1200 gph (30 gpm) but only when the lift and backpressure are zero. For real operation, you are operating more in the middle of the line, such 20 gpm and 10 psi of dynamic head.

The dynamic head consists of static head plus friction loss. For just pumping off of the bottom of a nearly empty tank, you might have 4 ft of static head and 6 ft of friction. A foot of head is 0.433 psi. If the tank is full, you can have almost no static head or negative because of the siphon action of the gravity on the water in the hose going down toward the drain.

The slower the flow, the bigger the pipe, the lower the friction. If you are forcing the pumped water through a filter, the friction could be considerable. The pump you chose to do that might not have the big gpm ability, but would have a higher head rating. If you are experimenting, maybe you can borrow a pump to proved out the concept. Remember to sanitize before putting stuff in your cistern tank.

Here are curves for 3 Zoeller utility pumps. Model 42 and 44 both have the same 20 ft head rating. But at 10 ft of head, the model 44 pumps more gpm. The model 46 might be a better choice to force water through a filter so that it can be returned to the cistern.

Would a backwashing filter, such as the TwistIIclean filter work nicely for you? Maybe model T2C-150. https://static1.squarespace.com/static/5af1e697f79392ad1c6690ba/t/5b084eb32b6a281a0b087f00/1527271095180/TwistIIClean+Brochure-v4.pdf
The Atlas Filtri Hydra is another backwashing filter. https://terrylove.com/forums/index.php?threads/atlas-filtri-hydra-video.69789/

I don't know if your sludge would cake up on the grid at the bottom of a utility pump, or flow thru.

 

[Eric70]

I'm thinking the guy who installed the chlorinator didn't understand that your cistern could precipitate the iron all on its own. My guess is he has probably sold the chlorinator and KL filter before to other homeowners with iron problems and it worked for them so that is what he sold to you. I also tend to side with the well drillers - don't put anything down the well unless you really need to.


It takes about 20 minutes for the iron to oxidize after it comes in contact with the air (or chlorine). Thats why it can look clear at first.

Your water is only partially oxidized by sitting in the cistern. The water really gets oxidized when it falls through the air when your cistern is filling (Your cistern does fill from the top, correct?). What the water sitting in the cistern is providing you with is time for the iron to move from a dissolved state to a solid one. You need 20 minutes from the time the water is oxygenated to the time it reaches the filter. You have much more than that so nothing to worry about there.


The answer is maybe. When I first installed my filter about 20 seconds into the backwash cycle I could see the iron in the waste water for maybe another 20 seconds if I was watching closely for it. More recently I noticed that I cannot see it anymore. I'm not sure what changed but I know the filter is working.


I'd say you don't need it and that its probably doing more harm than good in your system. As long as you have an air gap the water is falling though as your cistern fills I would turn off the chlorinator and see what happens. Worse case is you'll have to turn it back on again if the iron gets past your filter.

Thanks so much for your reply! The guy who installed the KL filter and chlorinator did a “well test” (yet, not a production test) when I was under contract on this home. With this being my first home purchase, and first time being on a well, I was completely oblivious, unfortunately. He recommended I replace the water treatment system that was installed in the home with the KL Filter and Chlorinator. As he told me, the chlorinator would attack the iron bacteria slime inside the well, and the KL Filter would treat the remaining iron.

He initially installed a Fleck 5600 valve, and set it to run a backwash every night to try and combat the iron. Made sense to me? (with how very little I knew ). I went out of town the day after it was installed, and came home to no water (up until that time, I had never had any issues with water quantity, nor quality). After two months of barely having any water, he finally contacted Fleck and learned that the 5600 valve was non-adjustable, and could use up to 150 gallons per backwash cycle. With my well only producing up to 50 gallons per day, it had no chance to recover from using that much water. He changed the 5600 to an adjustable 2510 valve, so I could at least minimize the backwash time (and gallons used).

As it turns out, with my well being run dry by the 5600 valve using more water than my well could produce, my pump continued to run and overheated into the PVC liner, and got “stuck” 800’ down (lesson learned: install a pumpsaver!). Ended up taking 4-days for the Well Specialist to get down to the stuck pump, and then replace it. It was after that that I had someone come out to do the production test (0.003 gallons per minute) and decided to add the cisterns. So, at least now I can visually see how much water I have, versus gambling like I was on whether I even had enough water to take a quick shower.

Frustrating, indeed. Yet, from what I’ve learned, it’s better to have cisterns full of iron and “sludge” (that can be cleaned out) versus that all developing in the well? Hopefully, the KL Filter can continue to do its job, as the water coming out of the filter, and into the home, appears pretty decent.

Thanks once again, as this has been a very confusing, yet educational, process!

 

[Eric70]

See https://www.superiorpump.com/products/utility/91250.html and click on the Specifications tab. You will see a graph and a table. It says that pump can lift 25 feet but only with the flow near zero. It can pump 1200 gph (30 gpm) but only when the lift and backpressure are zero. For real operation, you are operating more in the middle of the line, such 20 gpm and 10 psi of dynamic head.

The dynamic head consists of static head plus friction loss. For just pumping off of the bottom of a nearly empty tank, you might have 4 ft of static head and 6 ft of friction. A foot of head is 0.433 psi. If the tank is full, you can have almost no static head or negative because of the siphon action of the gravity on the water in the hose going down toward the drain.

The slower the flow, the bigger the pipe, the lower the friction. If you are forcing the pumped water through a filter, the friction could be considerable. The pump you chose to do that might not have the big gpm ability, but would have a higher head rating. If you are experimenting, maybe you can borrow a pump to proved out the concept. Remember to sanitize before putting stuff in your cistern tank.

Here are curves for 3 Zoeller utility pumps. Model 42 and 44 both have the same 20 ft head rating. But at 10 ft of head, the model 44 pumps more gpm. The model 46 might be a better choice to force water through a filter so that it can be returned to the cistern.

Would a backwashing filter, such as the TwistIIclean filter work nicely for you? Maybe model T2C-150. https://static1.squarespace.com/static/5af1e697f79392ad1c6690ba/t/5b084eb32b6a281a0b087f00/1527271095180/TwistIIClean+Brochure-v4.pdf
The Atlas Filtri Hydra is another backwashing filter. https://terrylove.com/forums/index.php?threads/atlas-filtri-hydra-video.69789/

I don't know if your sludge would cake up on the grid at the bottom of a utility pump, or flow thru.

Thanks once again, Reach! I’ll check those filters out and see if they may be able to filter out the ferrous iron as it’s coming out of the well and into the cisterns? The Superior Pump 91250 is the exact pump I was looking into. It’s sold online, and I thought I would give it a shot, and return it if it couldn’t handle the job. Like you, I’m skeptical on its ability to pump that sludge up from the bottom up to the top of the cistern and out to the drain?

I’m not sure if this is doing any good, or even a good idea, yet I’ve been periodically adding chlorine bleach to the cisterns in hopes that may work against the iron bacteria? I thought it may help with the oxidation process??