Help! BROWN IRON in pool water

[millspap]

Hi, I am a first time pool owner.

We have an 18 ft Intex pool that we just put up on June 30th. After two days to fill it from our well, it turned brown at the addition of the chlorine and we now know that this is the iron in the well water. Globules of rust are all over the pool sides giving the water the brown color, but the sample water itself is clear.

I have researched and found the homemade fiberfill filters that are supposed to help. My husband will be making one tonight when he gets home from work. Here is the info that I hope will help us with answering our problem.

July 2, 2015
8:00 AM
Pool temp 64 degrees
Filter shut off sometime during the night and we restarting it at 6:30 AM

1 1/2 gallon of bleach added the evening of July 1st

The test results from the Taylor K-2005 test kit are as follows:

Cyanuric acid - the test sample did not turn cloudy at all8.4
Total Alkalinity- 90ppm
pH-no color, tried base demand and couldn't add enough drops to get a color change.
Free Chlorine- no change I did the test 3 times, with 9mL, 4.5 mL and 1.8 mL
Total Chlorine- no change
Total hardness- I did the test twice, with 25mL and then 10mL for a result of 260ppm

Test results from Aqua Check-7 test strips
Cyanuric-30-50
Total Alkalinity- 120
pH-8.4
Free Chlorine-20
Total Chlorine-10
Total hardness-100

We would really appreciate any advice you can give to help us get the pool clear and swimmable.

 

[JVTrain]

A rise in pH will cause metals to precipitate out of the water, lowering the pH will cause them to dissolve again. It's odd that your K-2005 pH test gave no color as high pH shown in your suspect test strips would show up as a purple color. Did you try the acid demand test? Is your K-2005 new or could the reagents be expired?

I would suggest upgrading to a K-2006 or TF-100 that has a FAS-DPD FC/CC test that can accurately measure up to 50 ppm FC.

Metals in your pool can be a long, frustrating process to remove and keep from staining using sequestrants but check out this article for help: Pool School - Metals in the Water and Metal Stains

Welcome to TFP!

 

[millspap]

Thank you for the information. I read the article that you linked for me. If the iron can dissolve again by lowering the pH, it sounds as if I should use the muriatic acid that I bought.

I did not try the acid demand test, but I will tomorrow.

The K-2005 is brand new, so I don't think the reagents could be expired. Possibly, I just am not following the directions correctly. I will run all the tests again tomorrow and post them.

 

[Richard320]

My reply in this thread hold for you too. Follow the links and look

How do I remedy hard water I have to use for our pool

PS: another thread. Check the two pictures on page one and then go look at the filter on page two. Results of first TF-100 test ran on fill water

 

[TreeFiter]

Whenever I encounter iron that is discoloring water, I look at it as a blessing. If you can see it, it will filter. So let it filter out. Anything else you do will just hide it from sight, but it will always be there waiting for the right conditions to come back, or cause staining.

There is more to it than just elevated pH. Yes raising pH can cause Iron to precipitate, but it is not the only reason this might happen. One of the biggest factors is chlorine. Chlorine is an oxidizer. When you oxidize iron, you get rust. Rust isn't very soluble, so it shows up as nasty brown water.

I would run the filter 24/7 for a few days and clean the filter cartridge daily until the rust is gone. That way the rust will be taken out of the pool, rather than just dissolved back into the water until the next time you add chlorine.

 

[duraleigh]

There is more to it than just elevated pH. Yes raising pH can cause Iron to precipitate, but it is not the only reason this might happen. One of the biggest factors is chlorine. Chlorine is an oxidizer. When you oxidize iron, you get rust. Rust isn't very soluble, so it shows up as nasty brown water.

All well and good but that's a non-starter. Chlorine is totally essential for pool maintenance so it cannot be seen as the enemy. The enemy is iron.

Yes, having it precipitate is nice but as you continue to use it as refill water, the problem persists. The long term solution is to fill the pool with water that contains no iron. There are a couple of remedies if you put iron-laden water in your pool but they come with drawbacks.

Short of complete water replacement, your other option is a sequestrant. It does not rid your pool of iron be keeps it in solution. It needs to be replenished and is an ongoing expense you will have to deal with.

 

[TreeFiter]

You might want to give the CuLator a try. I've had reasonable success with it in several pools. There are situations where it does not seem to work, but this doesn't sound like one. Filter out what you can, and maybe see if the CuLator will remove the rest.

 

[zea3]

Throw those test strips away, they are wrong. Case in point, total chlorine is a sum of free chlorine plus combined chlorine. It is impossible for your free chlorine to be higher than your total chlorine. Strips in general are very unreliable for CYA results. If you have not added any CYA either from chlorine tablets or packets of "shock" then you have 0 CYA.

Filter the rusty water until it is clear or find a source of iron free water to fill the pool. Use sequestrant weekly to keep water clear.

 

[millspap]

My computer broke and so I was unable to get back to respond to all your helpful suggestions. My husband made a pool filter out of a 5 gallon bucket and fiberfill. It is working well and we rinse out the rust several times a day from it and the regular pool filter. The numbers are quite a bit different than the first readings that I gave you.
Here are my most recent:
July 3 , 2015

Pool temp 69 degrees
Filter ran all night


The test results from the Taylor K-2005 test kit are as follows:

Cyanuric acid - 0
Total Alkalinity- 110ppm
pH-7.2
Free Chlorine-0
Total Chlorine-0
Total hardness- 110ppm

I added 1 c acid and 2 1/2 oz soda

Results after 4 hours
Cyanuric acid - 0
Total Alkalinity- 110ppm
pH-7.4
Free Chlorine-1
Total Chlorine-1
Total hardness- 110ppm

July 4th 2015- No swimming today for us....still rusty but improving. Can see the bottom now.

Cyanuric acid - 0
Total Alkalinity- 110ppm
pH-7.4
Free Chlorine-0
Total Chlorine-0
Total hardness- 110ppm

The homemade filter hose popped off and about 10 inches of water ran on the ground before we noticed. Added more water and 6.4 oz chlorine.

We are wondering if we should be sweeping the sediment off the bottom of the pool or stir it up and let the fiberfill filter do its thing?

Thank you again for your input!

 

[Richard320]

If you can vacuum the sediment into the filter, do it. You want to see this:

 

[millspap]

Pool is clear! Thank you, everyone. Now my problem is that the chlorine won't hold. It comes up zero. I have been adding it at dusk.

 

[Richard320]

Pool is clear! Thank you, everyone. Now my problem is that the chlorine won't hold. It comes up zero. I have been adding it at dusk.

Have you added any stabilizer yet? CYA aka Cyanuric acid? Without it, pretty much any bleach you add will get destroyed by the sun within hours. And that leaves you chlorine-free and helpless for several hours each afternoon. I'd get some CYA in that pool ASAP and go heavy on the bleach. Hopefully, algae hasn't gotten a toehold.

 

[singingpond]

Pool is clear! Thank you, everyone. Now my problem is that the chlorine won't hold. It comes up zero. I have been adding it at dusk.

From your July 4 post, I get the impression that you may not have been adding any bleach to the pool while you were working on the iron problem... ? If you weren't, it's quite likely you have something growing in the water at this point, after that many days of 0 chlorine.

 

[singingpond]

If you can vacuum the sediment into the filter, do it. You want to see this:

This is what our filter cartridge looks like, for about one week (with daily or twice-daily rinses), at the beginning of every pool season. We've never had to rig up an auxiliary filter, as the OP did, but our iron levels may be lower. Having the iron precipitate out, with a particle size that can be caught by the filter, is a fortunate outcome, as a previous poster noted.