Yellow from chloride?

[Luc]

Hello, I was asked to take care of a pool some time and had to use chlore choc. As I didn't know it had to be put in the skimmer, I threw it directly in the pool. Now there are yellow traces on the bottom which I am almost sure are from these chlore choc and their movement.
Anyone had this issue and knows how to get rid of them?
Thx

[Teapot]

Yep, that's probably the cause, what is the pool made of, vinyl liner, glass fibre, plaster/tiles?
You shouldn't put Chem's in the skimmer either unless you are running the pump constantly until Chem's have fully dissolved

[Luc]

I asked the owners and it is liner....

So they say to put part of the Chloride to put in the skimmer and part in a floating container. There is a net in the basket of the skimmer, don't know if that helps. What other possibility is there?

[Luc]

So is there any solution for this @teapot?

[Luc]

I still looking for a solution....
Hoped you could help me further Teapot, can you?
Or someone else with similar experiences.

[Teapot]

No you have bleached your liner, nothing can be done until you change the liner. who are "They"? Too many bad advisers out there! don't put chems undiluted into pools ever and only in the skimmer when running the pump 24/7 until they are dissolved.

[Luc]

Oké thx, bad news hmm well can't change that anymore....
So if diluted you can put it in the pool?
And what about Chlorid which has to be dissolved gradually and the pump in rest during the night?
So I have to dissolve it and put it in.
The owners put the Chlorid in the skimmer for years and that seems to work though....it dissolves slowly or quickly, depending on the need of the water

[Teapot]

It's chlorine not chloride.
Lots of people put chlorine tabs in their skimmers. The tabs are very acidic and it attacks the pump and the plumbing and the skimmer when the water stops flowing because the pump is off.
It's very slow damage usually takes a few years but it's good for the pool industry as replacement of these parts costs owners. Tabs are meant to go in floating dispensers.

[Luc]

Thx for the lesson. I will update the owners.

[Teapot]

Sorry it's not better news.
The tabs will also build up the cyanuric acid (CYA) stabiliser above the limit of 50ppm and then maintaining the pool becomes tricky although the tipping point for loss of control seems to be 100ppm + of CYA.
We advocate changing to liquid chlorine/bleach once the CYA level is ok.

[Luc]

Never heard of CYA, how do you measure that?
I have those strips which measures 4 things: pH, alkaline, chlorine and how may particles per ...water (something like that the last one). The chlorine tabs are bind to something if I understood well and that rests in the water after the tabs dissolve. For that the backwash is important. Probable that is also a reason to better use liquid.

[Teapot]

Unfortunately test strips are at best a guess, some are marginally better than others but the issues are the colours and therefore the reagents run into one another, the length of time they are in the water is diluting the reagent and the colours on the packet don't match so guessing takes place.

The something the chlorine is bound to is the CYA stabiliser, some is necessary too much is bad. Easiest cheapest way of measuring is with the vanishing dot testers