BLUE TINTED WATER and STAINS???

[bluepool1]

I dumped my pool due to stains last Saturday (approx 10 days ago). Pool tests come up different every time now that the water is balanced. Some say iron or copper or both or none. The pool guy used muratic acid to wash my pool and then used a generic sodium bicarbonate to neutralize and we filled it with city water trucked in. The pool was crystal clear for 4 hours, I only added phosphate remover and salt and then water turned a tint of blue. It was not like this before we dumped it- it was clear water without the blue tint. I have since balanced the water, added GLB sequa-sol, filtered with new sand filter constantly and kept pool between 65-75 degrees. It is a 25k gallon salt water pool with a clorine generator. Staining is starting to reappear on the bottom of the pool and there is a light dark dust on the bottom that you see when you brush it. NO ONE IN MICHIGAN CAN FIGURE OUT WHY THE WATER IS A TINT OF BLUE and what is causing the staining to reappear. I do not want to dump a bunch of chemicals back in my pool and I really do not want to dump the pool water again. I have combed the web. Please help with any knowledge of something like this. HELP!

- blue pool 1

 

[tim5055]

Well, the best I can tell Sequa-Sol is a phosphate based sequesterant.

What stains were you having that you did a complete drain and refill? Did you identify the source?

My first suggestion is to dump the pool stores who had you add phosphate remover and a phosphate based sequesterant.

I have never seen it, but apparently copper can give a blue green tint to the water at times rather than the more common emerald green color.

 

[bluepool1]

Well, the best I can tell Sequa-Sol is a phosphate based sequesterant.

What stains were you having that you did a complete drain and refill? Did you identify the source?

My first suggestion is to dump the pool stores who had you add phosphate remover and a phosphate based sequesterant.

I have never seen it, but apparently copper can give a blue green tint to the water at times rather than the more common emerald green color.

___________________________
We have not identified the source of the blue tint or staining. The mercite/gunnite is approx 5 years old but the previous owners did not ever add calcium so it is pitted and we know that is one factor but just trying to figure out if anyone has ANY ideas where the blue tinted water and staining is coming from. Any ideas? Anyone out there had something like this? This may be the most annoying pool of all time since no one can figure out what is wrong with it and we already refilled it once just approx a week ago!

 

[TomBorg]

Was the pH of the water tested during the refill process?

I'm thinking the acid from the acid wash wasn't completely neutralized. Or a significant amount of muriatic acid went down into the main drain and wasn't neutralized. The acidic water then went through your copper heater coils, stripping copper from the pipes. This then turns the water blue.

If the person who did the acid wash is affiliated with a pool store, go to a different pool store to get your water tested for copper.

What is the pH of your pool water now? What was the pH immediately after the refill? Have you adjusted the pH since the refill?

 

[bluepool1]

PH was high after we refilled the water. The acid was neutralized using a baking soda generic brand though and some of the acid and baking soda residual inevitably remained in the new water. Does that matter? The PH is now balanced at approx 7.6 but being a saltwater pool, it always gravitates high. We use muratic acid to lower it. There are no copper pipes in the pool. We do have a waterfall attached with rocks dipping into the pool though so I guess that is another factor. Any ideas appreciated.

 

[tim5055]

Are you testing your own water, or using the pool store?

 

[bluepool1]

OK! I have a theory finally! When the pool was filling, I added salt. A few hours later it turned blue. The next day I noticed brown/orange stains starting. It was bad salt. Also, there was some iron in the fill water. Here is why... Salt had an additive called yellow prussiate of soda. Do not ever buy or add salt to your pool if it has this. It will stain your pool if any iron is present in your water. Also, I think I found something online that a chemical reaction between yellow prussiate of soda and iron can result in a "Prussian blue" color. Hence, the blue tint to water and the brownish/orangish staining in pool. What do you chemical geeks think? Does this make sense?

 

[chem geek]

"yellow prussiate of soda" is the same as sodium ferrocyanide decahydrate so has iron in the chemical compound itself. It is used in some types of salt as a non-caking agent. And yes, combining with oxidized iron (ferric) ions can produce the insoluble (or colloidal) Prussian Blue compound.

4Fe³⁺ + 3[Fe(II)(CN)₆]⁴⁻ → Fe(III)[Fe(III)Fe(II)(CN)₆]₃
Ferric Iron + "Yellow Prussiate of Soda" ---> "Prussian Blue"

So yes, I believe you figured out how you got iron into your pool and why the water turned blue -- it was a contaminant of the salt you used (plus iron in the fill water). Note that good pool salt (see Morton's, for example) does not have this anti-caking agent in it nor other metals. Solar salt (see Morton's, for example) similarly should not have metal ions in it and can be used in pools.

 

[pabeader]

You might have found the reason for my problem. I will have to do more research...