Can liquid chlorine damage fiberglass pool?

[tenkas]

This is a new pool, I had it for 1 summer and then it was closed in fall 2024.

Today, the person came to open it, saw that I didn't have any algecide (polyquat40 or 60 he was asking for) and said that I should NEVER put liquid chlorine in my pool orelse it will make the pool walls yellow (fiberglass pool).

The guy is old school, but he's been doing this for over 40 years so I trust him but wanted to have the opinion of TFP on this.

I was under the impression that it was ok to use liquid chlorine (bleach).

 

[mknauss]

Oh my. How misguided that person is.
Chlorine is chlorine. Your SWCG produces chlorine. Liquid chlorine is the same thing in water.
Only thing that can stain a fiberglass pool yellow is iron.

Algaecides are a waste of money. Chlorine keeps your pool algae free and sanitary.

 

[Jimrahbe]

Ten,

Once in the water chlorine is chlorine no matter how you add it..

It makes sense to NOT just dump a gallon of liquid Chlorine (Bleach) right into your pool with the pump off.. You need to slowly pour it in at a running pool return so that it mixes quickly with the water.

Thanks,

Jim R.

 

[tenkas]

ok that's what I thought, I am no chemist but I had the impression that the SWG generates the same "chlorine" as was is in the bleach.
Is it possible that some of his clients added liquid chlorine that contained metals or additive and stained their pools?

Also, he recommends that I put some Polyquat 60 for the algae to help clearing up the pool. Is this a good idea?

For now, he had me put granule pool shock (Dichlore from what I understand).

 

[ajw22]

The guy is old school, but he's been doing this for over 40 years so I trust him but wanted to have the opinion of TFP on this.

If you want to care for your pool like it's 1980, trust him; if you want to take care of your pool like it's 2025, trust TFP and ignore him.

 

[tenkas]

I do trust TFP pool, when the pool was running last year I didn't use any of the chemicals that the pool company sold me, just got the taylor kit, tested, and adjusted according to the test my SWG and my water was great all summer.

I'm just wondering why he thinks this will make the pool yellow.

I appreciate all the responses I get here, this is a great community.

 

[ajw22]

I'm just wondering why he thinks this will make the pool yellow.

You should ask him.

Maybe because if you look at liquid chlorine it is yellow when in the jug?

 

[JamesW]

Also, he recommends that I put some Polyquat 60 for the algae to help clearing up the pool.

I'm just wondering why he thinks this will make the pool yellow.

Because he has been trained by the big chemical manufacturers who want to sell algaecide and 100 other chemicals.

They tell you that liquid chlorine and SWGs will destroy your pool so that you need to buy hundreds of dollars per week of chemicals to prevent problems and then another hundred dollars of recovery chemicals when their strategy fails and your pool gets green, cloudy and nasty.

They sell you trichlor tabs and dichlor that run the CYA through the roof and then tell you to maintain a 1 to 3 ppm FC, which is a sure recipe for disaster.

Now, you needs 5 different types of algaecide including copper, silver, enzymes, phosphate removers, clarifiers, sponges, blah, blah, blah.

 

[tenkas]

Because he has been trained by the big chemical manufacturers who want to sell algaecide and 100 other chemicals.

They tell you that liquid chlorine and SWGs will destroy your pool so that you need to buy hundreds of dollars per week of chemicals to prevent problems and then another hundred dollars of recovery chemicals when their strategy fails and your pool gets green, cloudy and nasty.

They sell you trichlor tabs and dichlor that run the CYA through the roof and then tell you to maintain a 1 to 3 ppm FC, which is a sure recipe for disaster.

Now, you needs 5 different types of algaecide including copper, silver, enzymes, phosphate removers, clarifiers, sponges, blah, blah, blah.

I see! I personally much prefer the TFP method myself, and it has worked great doing the tests last year (at a certain point I was only testing every 2-3 weeks once I got the hang of it all).

With a SWG it was really easy.

Thanks for the info again.

 

[tenkas]

Hi!

Company came to open my pool yesterday.

They put in some shock (Cal hypo).

They told me to put algaecide but I decide to come here and was advices against.

I have my Taylor kit, these are the results.


My plan was to lower pH to 7.2 (which should bring down TA)

Add some cya (I have liquid) to bring to 30

Once cya is 30, start slamming pool until it clears up (it's nice but cloudy)

I am new by here, first time opening chemistry, I have read a lot but let me know if my plan makes sense.

I have put the picture of the pool yesterday (green) and today (much clearer).

I removed all debris, scrubbed, vacuumed.

 

[ajw22]

Lower pH to 7.2-7.4. Don't worry about TA.

Add the CYA and get the SLAM Process going using liquid chlorine.

 

[tenkas]

I just started the SLAM process today and the liquid chlorine I have is actually kind of yellowish.

General PDP Template

www.canadiantire.ca

It's suppose to be SHC - Sodium Hypoclorite, did I put the correct type of chlorine in my pool?
I believe that is why the pool guy says it will make the pool yellow, because the chlorine is yellow?

 

[mknauss]

Nearly all liquid chlorine (sodium hypochlorite) has a yellow tinge. It is from the process that creates it and it is iron that tints the product yellow.

 

[JamesW]

I believe that is why the pool guy says it will make the pool yellow, because the chlorine is yellow?

We cannot explain why the Pool Guy said it will turn the pool yellow.

You have to ask them why they said whatever they said.

 

[tenkas]

Nearly all liquid chlorine (sodium hypochlorite) has a yellow tinge. It is from the process that creates it and it is iron that tints the product yellow.

so if I understand correctly, there is a bit of iron in liquid chlorine?

 

[tenkas]

We cannot explain why the Pool Guy said it will turn the pool yellow.

You have to ask them why they said whatever they said.

When I asked him he just said: bleach is Crud, will make it yellow you can't use that.

No science behind it unfortunately.

 

[mknauss]

A bit. Not enough to create an issue. Especially with you as you drain / overflow water due to rain, winter, etc.

 

[tenkas]

A bit. Not enough to create an issue. Especially with you as you drain / overflow water due to rain, winter, etc.

I don't really drain much (only bellow jets to blow them) so about 1/10 of the pool I guess?

Then I fill back up and it stays full for winter.

Is there a way to test iron accurately? Or is this really a non issue?

 

[mknauss]

If you drain to below jets I suspect that is 30-40% of your pool volume.

It is a non issue.

 

[tenkas]

If you drain to below jets I suspect that is 30-40% of your pool volume.

It is a non issue.

Yeah I guess it's 1/3 because I lost 1/3 of my salt now that I think about it.

Google offered me also this explanation for the yellow:

Yellow Color:
The yellow color of sodium hypochlorite comes from the chlorine molecule itself, which has a characteristic way of interacting with light that results in a yellow appearance.