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Iron Stains


LBuehler

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Am new to the swim spa world. Have had the tub filled for about 2 weeks using an ozone and bromine. Had to leave out of town and was trying to get the Ph and alkaline levels up before I left. Alkaline for some reason was non existant and the Ph was about 6.2 or less. Was using Leasure time spa up and it seemed I was still not seeing much if any change. The next morning the tub was green I dumped about 2 1/2 boxes of baking soda in and the alkaline levels came up to 120ppm and the water was clear. When I got home from my trip 2 days later the water was brown the the white tub is stained brown and black. I immediately dumped some metal control which helped and was finally able to stabilize the Ph at 7.4 but the damage was already done. Never knew this could happen. Equipment ok. I drained the tub. With comet the stains barely come out. Has anyone experienced this and if so what did you do? Any one have some good advice on how to proceed. The tub is about 4000 gallons.

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refill the tub and follow the bromine for beginners guide to get it started.

take an ordinary vitamin c tablet and hold it on one of the stained areas for about thirty seconds and report back what happens.

Also please post a full set of water test results not done with strips. If you are using bromine then you need to post bromine, pH, TA, and CH (not total hardness). Also, if you could get your water tested for iron and copper it would be helpful but if you put in a seqestrant then it is probable that any test for metals will not register any even though they may be present.

Do you fill with well water?

DId you create a bromide bank with sodium bromide when you filled the spa? Do you use bromine tablets in a floater or feeder? What do you use to oxidize the bromide besides ozone? (Chlorine or MPS?)

DO NOT SCRUB THE STAIN WITH COMET!!!!!! YOU WILL DESTROY THE SURFACE OF THE SPA!!!! ALSO, IF IT IS A METAL STAIN THE CHLORINE IN THE COMET COULD MAKE IT WORSE!

POST THE TEST RESULTS, REPORT WHAT A VITAMIN C TABLET DOES, AND ANSWER THE OTHER QUESTIONS and we can take it form there.

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Appreciate your response. thank you. Started to clean with comet but only got a little way. Very hard to take off. I work a lot of hours so give me a few days to get this done. Will fill it back up tomorrow. No well water. Used feedes with bromine and added bromine to tub after initial fill. Oxy spa non chlorine shock. Used bromide booster to get my bank.

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Do you think it is possible to get the stains out after filling? 4000 gallons is a lot of water to fill and empty? Are you thinking that the tub chemicals will naturally bleach it out? Will be filling tonight as you originally suggested. Takes 5 hrs to fill. Thank you

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Try a wet viitmain c tablet on the stain.and report back.However, black stains sound a lot like copper and they can be toublesome to remove. However, they are removed with the spa filled since we need to get the metal to dissolve back into the water.

I assume the swim spa is fiberglass

I assume it has a heater with a copper heat exchanger

For some reason your pH was VERY low (and it seems you are testing with strips, which are uselss!)

You said something about trying to get the pH and TA down so I assume you just dumped in a lot of acid and that is why the pH was so low..

I am guessing (actually I am pretty sure!)that the low pH attacked the copper heat exchanger (would be a good idea to have a service tech check it out) and that is how the copper got into your water

You started dumping in Spa Up (sodium carbonate, washing soda) and the water turned clear green and stained black (copper). Iron would have either turned the water yellow or precipitated out as rust. IF the spa is blue then it might look green because yellow water against a blue spa would look green but the staining would not normally be black.

Is this pretty much what happened?

How high was the bromine at this time?

You were testing your water as you tried to adjust the levels AND computing how much product to add the make appripriate changes, RIght?

(Dump and go just does not work, as you have seen!)

Copper turns water green and stains black, redish brown, or bluegreen. The black copper stains are in an oxidation state that are very difficult to remove.

Please list ALL chemicals you have put in the spa since you filled it and what you have been testing the water with

Please read the sticky on Bromine for beginners.

Please let me know the results of the vitamin C test.

Do NOT try and scrub off the stains, it won't work and you will ruin the spa surface (and possibly the spa).

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Just wanted to say thank you for helping me out. The fact that this happened has really stress me out. Tried the vitamin C rub and it seemed to be white in those spots. :)

In answering to your previous post The swim spa is fiberglass white. i do have a boiler with copper heat exchanger. My Ph was very low and no test strips. Taylor K 1004.

I dont think I dumped any acid in. I was trying to raise the Ph and alkaline levels. At that time the Bromine was 1 Ph was a very yellow 6.8 and the alkaline test was automatically red never green. Good guessing but you were close. Boiler is not leaking that is a very good sign.

Was trying to get the bromide levels up adding Spa choice bromide booster when the water turned yellow. Also was adding spa choice liquid spa up to raise both the Ph and alkaline levels. Could not get them up. Next day water was green. Used baking soda 2.5 boxes and the water immediately cleared. At this time the Ph was the same and Alkaline was 120ppm. That evening the water turned chocolate brown. Panicking Tried the spa choice clear and sparkle Oxy spa Non chloirine shock ( which I used in the past to try to raise the bromine levels). It did nothing. Ran down and bought some Hth ph plus and Hth metal control. Got the Ph up to 7.8 and dumped the metal control in but by that time the damage was done to the sides....Stained. Not knowing what to do I drained the tub 16' x 8' x 4' and was starting to used some comet. Thats when I posted on here for help!! I do have an electronic ozone and have two small floaters.

Right now I am filling the tub and will follow the Bromine for beginners guide. Is the Bromine booster the right stuff and is the Oxy spa what I want to use to shock the spa to get the Bromine levels up. When the tub was being used everytime I came home their was always people in it. Kids and neighbors. It gets used quite a bit. My house has always been a kid magnet with my girls now its really popular. PS no test strips....

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If the bromine booster is sodium bromide it is what you want to use. What are the ingredients in the oxy spa and the bromine booster? Before you add any it would be better to treat the stains. You will need ascorbic acid powder (you will probably need to order it from the internet from a place like the Chemistry Store but you might be able to get it fron a drug or health food store also. You need pure ascorbic acid powder AKA vitamin C powder) You want to add 6.5 oz by weight to your filled spa pH at about 7.2-7.4. TA below 100 and NO sanitizer and circulate until the stains are gone. After about 2 hours of cirulaton add a HEDP based metal sequeatrant (Jacks Magic pink stuff or Proteam metal magic are both HEDP, many are not). for your spa you need to add 4-6 oz. If you need to lower the pH down ot 7.0 to continue lfing the stains do so but not any lower , use your acid demand test.

Once the stains are gone DRAIN AND REFILL!!! All the metal is dissovled in the water and you want to get rid of as much of it as possbile so you don't restain.

Once you do that follow bromine for beginners

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Just asking if 6.5oz is enough vitamin C. Also if the Ph drops how much Ph plus should I add? 3800 gallons. Ta is 20ppm and Ph is 7.2 Ph after adding the vitamin C

You said you have a K-1004. It has acid and base demand tests. Use them. You do NOT want to add pH plus. that is why you use a demand test to see exactly how much acid you need to drop the pH to the desired target. Personally I think you should get a K-2106 test kit. It has a more precise pH test and a higher precison acid and base demand test in addition to an FAS-DPD titration test for bromine which is much easier, much wider range, and MUCH more precise.

Vitamin C is dosed at 1 lb per 10 k gallons so it si the right amount for 4k gallons. More is not better. If one treatment does not remove all the staining it is better to repeat the treatment.

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I did add some Ph plus to keep the Ph from going below 7.2. My last tests which have been pretty much consistant all day are Ta 30ppm and Ph 6.8-7.2. Have been babysitting this all day and have seen little to know affect. Doesnt the acid demand test show me how to lower the Ph when my Ph is already too low? You asked me to keep it between 7.2 - 7.4 at which i have been trying. I am at a loss now :(

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acid demand test tell you how much acid to put in to lower the pH when it is too high. Base demand test tell you how much soda ash to put in when the pH is too low. However, it is better to use double the amount of borax to bring the pH back up since it will not cause the TA to go too high as soda as often does.

Have you put in the ascorbic acid and the metal sequestant like I said?

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It's why we are here. ;)

Keep us posted on the progress. As I said, you want to drain to get the dissolved metal out of the spa and you might need to repeat the process. IF you only have a lttle bit of staining left then you can put a bunch of vitamin C tablets (from the drugstore) in a white cotton sock ans use it to wipe the stains away before you drain and refill.

If there is a bit of staining left then you might have to live with it. Keep the pH at the low end of acceptable (7.0-7.2 and don't let it get above 7.4) and keep adding a HEDP based metal sequestrant and the rest of the staining should be gone by the time you are ready for your next drain and refill (except where you damage the gelcoat with Comet, unfortunately)

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Appreciate your help. In the process of draining. Will try the Vitamin C rub. Most stains are gone. As far as the gel coat I was very adimate about not to scratch. And your right what is left I can live with it. As time progresses maybe it will bleach out on its own. Thanks

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OK now its been a few days since our last chat. I have filled the tub but being a rookie especially with 3800 gallons it is a little difficult to get the Ta Ph in line. Almost their. All stains are gone!!! Can you tell me how much baking soda, Muratic acid, bleach, And borax to use per gallons to either lower Ph and or Ta and boost. If I had a typical spa we would be talking table spoons but everything I have read calls for cups! Thanks for all your help and support.

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Your test kit (if you have the one you indicated earlier, K-1004) has acid and base demand tests and using those tests are the only way to know how much of a chemical to add to raise or lower pH. If you need to raise pH I would use twice the amount of borax in place of the called for amound of soda ash (( pH increaser) since it will have less negative impact on TA. How much you need to add depends in part on the current TA and how much of a pH change is desired, which is why the demand tests are the only way to really know. If you DON"T have the kit you said that you did (K-1004) then you need to get a Taylor K-2106 test kit (IT has a MUCH BETTER bromine test and includes the Calcium Hardness test and a moer precise pH test with more precise acid and base demand tests.).You still need to suppliment your kit with the Taylor Calcium Hardness test kit because you also need to monitor that

As far as how much sodium bromide and bleach you need. It is still the same as indicated in bromine for beginners. 1/2 oz per 100 gallons on filling so that would be 5 oz per 1000 gallons or about 19 oz for your 3800 spa. Shock it with bleach at a rate of about 2 oz per 100 gallons or, for your spa, 76 oz, which is a cup and a half more than half a gallon.

IF you need to lower TA follow this sticky

IF you need to raise TA 9 oz by weight of baking soda will raise 3800 gallons 10 ppm (this is approx 7 oz by volume measurement, btw.)

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I do have the K 1004 test kit. Ta is 120 after adding the recommended dosage of Borax to get it to that level my water has a white film on it now. Ph is low will need to areate the tub but my pumps are currently not working. Any suggestions? Added Sodium bromide for the boost and shocked with 6% bleach which turned the water green tint. Only put in the recommended dosage. My bromine levels are still high. Seems I am almost their but not quite. This stuff is probly easier to do in a 3-400 gallon hot tub. When you add something to make a change in the water how long do you wait for a correct water test?

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What are your current test results? I need results for pH and also for bromine. If it is too high to test then dilute a sample of your pool water with distilled water and test as follows:

IF you dilute 1 part pool water with 1 part distilled water multilply the test results by 2

IF you dilute 1 part pool water with 2 parts distilled water multilply the test results by 3

IF you dilute 1 part pool water with 3 parts distilled water multilply the test results by 4

IF you dilute 1 part pool water with 4 parts distilled water multilply the test results by 5

Start with the 1:1 dilution and go move to the next if you are still off scale.

You do lose some accuracy with each dilution BUT it does allwo you to get an idea of about how high your bromine really is. This is why I prefer the K-2106 test kit. IT will allow you to directly test bromine levels above 25 ppm with a precision as great as .5 ppm and is not a color matching test. It is a drop counting test like the TA test with a color change from red to colorless.

As far as water balancing being easier in a small tub, not true. Larger bodies of water are more "forgiving" of mistakes in dosing or inaccurate water capacity numbers. For example, being off by 20 gallons of water in a 380 gal hot tub is a bigger error than being off by 100 gallons in a 3800 gallon hot tub and adding an extra ounce of baking soda to either is going to create problem in the small tub but will hardly be noticable in the big one.so very accurate measurments are much more critical with the smaller body of water.

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How can I lower my Ta without lowering my Ph?

You can't.

The act of lowering the pH lowers the TA (but you do not want to drop the pH below about 7.0)

Aeration then brings the pH back up by outassing CO2. This is the ONLY way to raise pH without raising TA again.

The process is repeated until you reach your goal

Read this!

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Well I did it!!! Wooohoooo Took trial and error 4 times drain and fill. Right now

TA 80

Ph 7.4

Bromine very high due to shock

Water crystal clear

Appreciate all your help. Thank you Also took your advice and upgraded my taylor kit to the one you suggested K - 2106... Happy swimming :)

Will be in touch

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