Metal stains reappeared after Jack's Magic

[beekrock]

I'm flipping a house with a 20,000 gallon in-ground pool with a vinyl liner. The liner had/has yellowish mottling throughout. I used Jack's Magic Stain ID Kit and the solution was Solution #1 (Jack's Magic Iron, Cobalt, and Spot Etching). I used the product and the next day the stains were - like magic - gone! Since the chlorine was just below 1ppm for the stain treatment, I started with 5 gallons of liquid chlorine the first day and 5 gallons the day after that (which was today). Well, by this afternoon I noticed that the stains were back, albeit to a slightly lesser degree, AND the water had taken an a slight greenish hue. So, this morning the liner was clean and the water was blue, but in a matter of one afternoon the stains came back and the water was greening.

I should note that, like an idiot, I didn't add a sequestrant so I understand why the stains are back, but why the greenish water?

Do I need to bite the bullet and start the process over with the Jack's Magic, or is there something else I can buy that would be cheaper and just as effective? I'm trying to get this pool looking good ASAP, as I'm listing the house for sale!

Im not at the house right now, so I don't have the water specs to post, but they were all within the required range for the Jack's Magic Stain ID.

 

[beekrock]

I forgot to mention that there was a higher level of copper present in the water. I'll post my water specs in the morning when I get them.

 

[TomBorg]

As duraleigh pointed out in this thread, if you have iron in your water, adding chlorine can make the water suddenly take on a green tint. Since you added 10 gallons of liquid chlorine to a 20,000 gallon pool, your Free Chlorine level is likely up around 60ppm (depending on the strength of the chlorine), which is insanely high.

Copper can also create a green or blueish tint.

Once you get your tests done (I assume you're having it done at a pool store, which means the numbers will likely be inaccurate), check your chlorine level vs your CYA level as shown on this chart: Chlorine/CYA Chart. If your chlorine is above the shock level for your CYA, you should get some sodium thiosulfate to reduce the chlorine back to a reasonable level.

Then add another batch of Jack's Magic. Sequestrants don't get rid of metals, they simply bind to the metals so they don't stain. But sequestrants degrade over time, so you have to replenish them on a regular basis.

 

[TomBorg]

Oh, the pool store testing will probably tell you your pH is too high, and they'll try to sell you some expensive powdered acid. Don't bite. High chlorine levels will skew the pH test to read falsely high. Wait until your Free Chlorine (FC) level is back down below 10ppm, then retest to see if your pH needs adjusting.

 

[beekrock]

60ppm!!!!! Not only did the guy at the pool store tell me to do that, but he also told me to add more! Unbelievable. I'm going to a different pool store tomorrow for sure.

Any chance of that high of chlorine level damaging anything?

 

[TomBorg]

60ppm!!!!! Not only did the guy at the pool store tell me to do that, but he also told me to add more! Unbelievable. I'm going to a different pool store tomorrow for sure.

Might be a good idea. This is another example of why pool stores get no respect around here. This kind of thing happens all the time. The clerk heard "green", and thought "needs more chlorine!" without asking any questions or testing the water. And then they sell you more stuff to try to fix the problems that they caused.

Any chance of that high of chlorine level damaging anything?

Yes, but don't panic. It takes time. From the pictures, there's enough particulate matter and leaves and stuff to use up some of the chlorine, and some will be burned off by sunlight. Make sure to leave the cover off of the pool until you get the chlorine level down. As long as you can reduce the chlorine to a reasonable level tomorrow, you should be fine. If the pool store can't get a reading on the chlorine because it is too high, have them do a dilution test, where they do 1/2 pool water with 1/2 distilled water, then redo the test, and double the result. You want an accurate number so you can calculate how much sodium thiosulfate to add (if you need to add any).

Chem Geek posted a very helpful response in the other thread that I mentioned above.

 

[Swampwoman]

I don't know how much time you have or whether you intend to have a pool at you new home, but you would benefit on many levels from having a proper test kit and reading up in pool school so you're not at he mercy of idiot pool stores

The TFT kit and/or Taylor 2006 specifically are accurate and can read high levels of chlorine -- and equally as important in the case of managing metals -- accurate ph levels. Here's a link: TFTestkits.net

Treating metals is a fairly precise business with a lot of room for unintended outcomes With any treatment, you generally want to keep lower ph, eg. 7.2, and to bring the chlorine back up in a slow, controlled way to avoid both the return of stains and/or oxidizing metals in the water instead of sequestering them, which is what hapened to you.

In your case, since you started out with jacks, might as well use Jack's sequestrant to see if it will get it back to where the treatment had it. I would in this case use a full startup dose, or possible more. But I would first neutralize the chlorine because both Jacks and Metal Magic aren't effective if used when FC is high. I have this on authority from one of the mfgs

Both Jack's and Metal Magic sequestrants are recommended here. The only real difference with Metal Magic is that your ph needs to be a 7.6 for ideal performance, which I like, instead of the lower ph required by Jack's. I have well iron, and have been able to clear stains with a megadose (eg 5 bottles) of Metal Magic, and now use that to maintain. But jacks works well too, and no sequestrant is technically meant to clear stains per se, merely to bind up the free metal in your water. (I used to do Ascorbic Acid treatments but having low, protracted chlorine, adding polyquat, etc. felt like more of a hassle than the megadose of Metal Magic...the latter isn't sure fire in all situations, but works in mine.)

Let us know how it goes but when you're picking up sequestrant, also see if they have chlorine neutralizer, but use carefully to get the FC down and make sure you don't let the water linger at too low an FC for long or you'll have another kind of green to deal with.

Best wishes!

 

[beekrock]

Thanks, everyone. I ordered the suggested test kit on Amazon. In the meantime, I bought a cheaper one to tide me over and had the pool store test the water while I was there:

The store's system stops at 15ppm, so I assume it's significantly higher. I bought chlorine neutralizer and, according to the chart, I didn't have enough to drop it as much as I wanted, but I did use the whole container.

I've also been playing around with the cheapo test kit. Before adding neutralizer, straight pool water was reading 2ppm. I then diluted it to 1 part pool water to 3 parts distilled water and it still shows as 2ppm??? Diluted it a few more times and still was getting 2ppm???

Several hours after adding neutralizer, straight pool water was still showing up as 2ppm. Diluting 10 to 1 showed up as 1. This picture is the result of 15 to 1 dilution:

I'm going to get more neutralizer and have the store test the water again. I'm afraid of adding too much neutralizer, so I think I'll take my time with this.

 

[TomBorg]

The problem with those cheap tests is that high chlorine levels can bleach out the indicator dye, and make the test read a false low.

Your dilution test is interesting. The more you dilute your sample, the more inaccurate the test can be, but in this case you don't need much accuracy. The 15-1 dilution suggests your current FC is most likely somewhere between 15 and 30ppm. So adding enough sodium thiosulfate (or sodium sulfite) to reduce your FC by another 10ppm should be a very safe step.

The next time you go to the pool store, you could bring a 1-to-1 diluted sample, and multiply your results by two.

 

[jblizzle]

With a Taylor yellow OTO test, you can get a sense of high FC as it will turn dark yellow, orange, deep orange, brown as the FC gets higher. No idea if that cheap test works well enough to do that ... it appears not.

The FC will drop on its own from the sun, I see not reason to try to actively lower it.

 

[beekrock]

I just got back from the pool store and the undiluted pool water tested at 7.4 ppm. I also tested it myself diluted 4 to 1 and it appears to be about 8 (2x4). I won't be buying anymore neutralizer.

Terrible timing, but I'm going away for three nights starting Sunday. Any suggestions for what to do before I go? Turn the chlorinator back on, but keep it on the lowest setting? Keep the chlorinator off?

 

[jblizzle]

If you think the CYA is low enough to handle going up some, you could use the tablets.

 

[TomBorg]

But the water has lost the green tint? Congrats! Now get that puppy sold!

 

[beekrock]

It definitely got bluer and the stains have lessened - and only I n a matter of several hours! I'm hoping that as the chlorine level drops a little more that it will clear up even more. Time to sequester this d@mn metal!

On a side note, there are several rust spots on the bottom that never came out with the Jack's Magic and are there now. Anything extra I can do to get a rust spot up? There were a few pipes and chains in the pool when I bought the house.

 

[TomBorg]

Ascorbic acid (aka Vitamin C) will pick up rust stains. But it will make copper stains worse, so be careful.

Crush a bunch of Vitamin C tablets, put them in a sock, tie it up, and drop it on the stain. Let it sit for 30 seconds, then move it to the next stain. If the stain got lighter, it was iron/rust. If the stain got darker, it was copper. If no change, try again.

If the stain is organic, rubbing the stain with a trichlor tablet can lighten or remove the stain.

 

[beekrock]

Just a quick update:

I came home to a nice, blue pool this afternoon. It looks a tiny bit cloudy, possibly from the heavy rain or low chlorine level during the stain treatment. The rust spots also look to be lighter even though I haven't treated them with vitamin C tablets yet.

The Jack's Magic mentions to re chlorinate slowly after treatment and not to shock the pool for a week to prevent the restaining that happened last time. I turned the chlorinator on today and set the dial to the middle setting. Should this suffice? The chlorine was at 0ppm when I tested it today. I'd hate to add too much, but I'd also hate to add too little.

 

[DaninFLA]

that picture just makes me laugh. recommended CYA: 30-200, haha. but then the recommended FC level range is 1-3ppm. its like they want your pool to get algae so you come back...oh wait, that's exactly right.

 

[chem geek]

The Jack's Magic mentions to re chlorinate slowly after treatment and not to shock the pool for a week to prevent the restaining that happened last time. I turned the chlorinator on today and set the dial to the middle setting. Should this suffice? The chlorine was at 0ppm when I tested it today. I'd hate to add too much, but I'd also hate to add too little.

Check the chlorine again and if it's still zero then add some manually (chlorinating liquid or bleach) because you might already have nascent algae growth. If the chlorine is starting to come up, then just see how it goes and adjust accordingly. Raising the chlorine level up to around 5 ppm should not be an issue. You just don't want to raise up to 10 or more quickly where the issue isn't just the chlorine level but the rise in pH (though higher active chlorine does break down the Jack's Magic product faster).

 

[beekrock]

THE STAINS ARE BACK!!!

I don't understand!?!? I followed the Jack's Magic instructions to a tee. I rechlorinated slowly, never shocking and never going above 3ppm, yet the metal stains are back. I've also been adding 16oz of Jack's Magic Blue Stuff per week.

The good news is that the house went under contract in 4 days, but I'd really like to have the pool looking nice for when the buyers come back to show their friends & family. What am I doing wrong?

Here are some of the numbers that may or may not be pertinent:

PH: 7.5
CYA: 55
Total Chlorine: 3ppm
copper: .5
iron: .2

 

[chem geek]

Lower the pH and add more sequestrant. Call up Jack's to see what they say to do.

If you weren't in the process of selling the house then I'd suggest some other methods to physically remove the metal from the water, but those methods take longer and you don't have that kind of time and they aren't guaranteed to work (except for water dilution).