"Expert" needs help. LOL

frustratedpoolmom

TFP Expert
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In The Industry
May 20, 2007
12,237
Key West, FL
Ok, I'm stumped, never seen anything like this before.

Here is the pool as I arrived. Opened by homeowner 24 hours ago. Nothing added.

CAM00033 by poolmom11, on Flickr
PH test came out pale yellow - not even registering.
TA test registered nothing. It turned a color I've never seen. FAS DPD turned pink for 15 seconds then turned clear. Ammonia test negative.

I added enough baking soda to reach 60. I poured in it front of the return in the shallow end, and before our eyes, the color change in this pic happened...

CAM00034 by poolmom11, on Flickr

I added 2 lbs of Borax. Whole pool turns blue, all yellow gone. PH test a little bit later turns a neon purple color. I didn't understand how I could overshoot with 2 lbs! For kicks I pour a small amount of Muratic Acid in the water and the original yellow color started to return. I added more baking soda and that stopped.

The TA test is now the Blue/Yellow combo we see at high chlorine levels. But none has been added! At this point I pour in a gallon of 12.5%. FAS-DPD test does the same thing.... turns pink then clear on its own. If I add drops, then the drops for the CC test, it turns a cloudy brown. What the heck?!

I had to leave cuz I work my night job at 5:30 but I'm stumped, told them I would be back on sunday. At least the pool is a pale greenish blue.

Any thoughts?
 
I'm starting to doubt metals as well since raising the ph seemed to cause the color to disappear.

I realize you do not believe chlorine has been added and I am not sure about your description of "neon purple" for ph, but is it possible if your FC is really high, you could have converted to Chlorphenol red (as dicussed in the extended test kit directions) since the ph is apparently low? I would check the chlorine with the OTO test and see what color you get.
 
Very strange.

I'm thinking possibly very high bromine levels with very low pH. With that combination, you can begin to get elemental bromine, which is yellow at high concentrations and brown at super high concentrations.

I'm thinking the pH neon purple was bromophenol red.

I would suspect that the pool has been run on bromine tabs for a very long time without proper chemistry testing.

This might be a situation where you have to drain and refill. However, it looks like a fiberglass pool, which can be a high risk for floating if the water table is high.

acid-turns-yellow-when-added-t27500.html
 
linen said:
I'm starting to doubt metals as well since raising the ph seemed to cause the color to disappear.

I realize you do not believe chlorine has been added and I am not sure about your description of "neon purple" for ph, but is it possible if your FC is really high, you could have converted to Chlorphenol red (as dicussed in the extended test kit directions) since the ph is apparently low? I would check the chlorine with the OTO test and see what color you get.

The pool owner insisted that nothing was added. He didn't top off, it was full from rainwater. I was getting these strange colors on ALL of the tests before I added chlorine.

It turned neon purple before I added chlorine.... when you are typing a response and the font colour selection is on the right - see those shades of purple? That's the color. LOL

:oops: I'm out of OTO. :hammer:
 

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Fun chemistry experiment :)

There is certainly iron in the water, and I suspect that the FC level is really high. Everything described points towards both possibilities.Your test description strongly indicates very high FC levels, and at very high FC & pH levels iron in the water would turn yellow/green/brown as iron goes through various oxidation states.

Try the FAS-DPD test again with twice as much R-0870 powder. By the by the sample turning pink then clear or pink then brown are both indications that you need more R-0870 powder. I also suggest adding a startup dose of sequestrant, which should clear the color up more quickly, though simply letting the FC level come down and then adjusting PH will probably do the same thing but take more time.
 
All he said was he had opened it the day before and had not added anything. Husband was at work, wife knew no details.
It didn't really smell at all. There was no tablet feeder, so I really don't know. CYA was zero. I'm guessing they closed it without checking PH and TA. Its just bizarre. Headed back there this morning, wonder what I'll find.
 
With that white fiberglass, iron should be leaving stains. Is there a source of iron or other metals, such as a heater or well water? Have you tested for iron?

What type of filter do they have, and have you opened it to inspect if cartridge or DE? Or, backwashed, if sand? What did the elements, or backwash water look like?

What chemical containers are on site?

The more details you can provide, the more likely it is that we can reach a reasonably certain diagnosis.
 
Cartridge, didn't open... now that water is blue and clear they are happy but I need closure. LOL.

Iron tested zero. (Did it precipitate out? Is that all the Crud on the bottom?)

TA is now 80... def reacted like high FC (blue to yellow).

PH still purple.

CAM00037 by poolmom11, on Flickr

Decided to try the 2 scoops of powder and FC registered at 31. I added ONE jug of 12.5 last Friday. They SWEAR they added nothing upon opening and nothing since... somebody ain't tellin the truth! One gallon in this pool (says it's 10,000 gallons but I think it's closer to 8000, wouldn't be more than 15 or 16 at the most...
 
The PH test turning purple is expected when FC is 31. Likewise the FAS-DPD test going pink and then either clear or brown is common enough when FC is that high. So everything fits well enough.

The remaining mystery is how the FC level got that high, which in my book can be dismissed as "these things happen". But if you do want to pin it down you have to ask, is there any chance they have a SWG that has been running this entire time? Or another pool service? Or a helpful neighbor?
 
Spa Clear Yellow Water
Spa water that is tinted clear yellow usually indicates a high bromine residual and a low pH. This is fairly common with bromine spa systems, because the bromine can discolor the Phenol Red used to test pH. The pH reading looks higher than it actually is, which often causes the mistaken addition of more acid. The higher the bromine reading, the more tendency to discolor the pH test, so it can become a vicious cycle.
http://www.vaughanpools.com/pdf-files/S ... rouble.pdf
Clear water with a yellow tint usually occurs in bromine systems. The water can take on a slight discoloration if the bromine level is too high and the pH is too low.
http://www.rhtubs.com/store/essentials- ... NATEDWATER)
The lack of cyanuric acid helps rule out trichlor pucks. The iron tests as zero. However, there are reasons that it could be iron and not register on the test.

I think that the most likely cause is use of bromine tabs. That would explain the low pH. The pH color is a false high due to the halogen level.

Are the homeowners not able to provide any information on what they routinely use to sanitize?
 

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