Pool chlorine/salt levels (again)

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Trooperman
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Pool chlorine/salt levels (again)

Postby Trooperman » Sun Oct 29, 2017 11:57 am

I know this subject has appeared before, but most of what I'm now worried about was partly discussed many years ago and contributors will have changed so I'd be grateful for the latest thoughts please!.....and we start from the basis of me being "O" level Chemistry failed :oops:

I have a (new to me) medium sized pool with a Zodiac automatic thingy (is it an electrolytic device?) which I thought arranged the chlorine/salt levels and an equally automatic pH thingy which pumps, if required, acid from a container to maintain the correct value of that reading. When I bought the house and pool it was said that it was a salt water pool that "occasionally needed some chlorine added". That confuses me!

As I am, as mentioned, chemically "inert" in the brain department, I use a simple 5 drop liquid test kit for checking these measurements. The pH is always spot-on at 7.4/7.6 but the other one (chlorine or salt?) is now the colour of a blood orange when I add the colourless chlorine/bromine test liquid and tallies with none of the straw coloured test marking colours.

So, you can glean from this that I don't really have a clue as to what's going on :lol:

Can anyone please enlighten this ignoramus?
nil illegitimum carborundum

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White Horse
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Re: Pool chlorine/salt levels (again)

Postby White Horse » Fri Nov 03, 2017 12:03 am

Sounds like you have a Zodiac salt water chlorination unit and you have been running the pump too long. You will need to run the pump for less time to allow the chlorine to dissipate.
Beachcomber will be along shortly to tell us how much he hates salt water pools. ;)
The electronic device you have is a set of plates which when switched on (with the pump) separates the Sodium and Chlorine in the Salt, into ions, which I think forms sodium hydroxide in the water and provides free chlorine.
Now that the water is cooling down and there is less sun, the chlorine is not lost so quickly. I bet there's not a trace of algae in your pool!
EDIT
What settings have you got on the chlorinator? It might be possible to turn it down and/or reduce the pumping hours.

Beachcomber
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Re: Pool chlorine/salt levels (again)

Postby Beachcomber » Fri Nov 03, 2017 8:48 am

I have come along to say how much I hate salt water pools!

I much prefer that chlorine is made, under control, in a factory rather than by some dodgy chemical process in my back garden. I know several people who either inherited a so-called salt water pool or had one installed and have since ripped it out in favour of a proper sanitisation system

You should start by getting a proper test kit similar to this:

Image

The liquid test kit measures combined chlorine rather than free chlorine. The five drops system is inaccurate, the liquid has a very short shelf life beyond which it gives false readings and orthotolidine (OTO) has been banned in many countries. The test strips are totally useless and do not give an accurate reading.

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Trooperman
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Re: Pool chlorine/salt levels (again)

Postby Trooperman » Fri Nov 03, 2017 10:34 am

OK Beachcomber! I understand your detestation of the method! :lol:
I will ask my local pool shop (in Antequera) for measuring options.

BUT....I do have my own "litmus" test and that comes in the shape of any one of my seven cats: if they drink from the pool, all is OK!

What settings have you got on the chlorinator? It might be possible to turn it down and/or reduce the pumping hours


There is a button to press, labelled "Output Level" that, when pressed, lights up green diodes and there are 4 such diodes/levels. Mine was set on the maximum of 4 and I've now reduced that to 1: we'll see what happens. The automatic pump was set to come on for two, 1 hour session each day.

But I'm confused about this:
separates the Sodium and Chlorine in the Salt,
. Does that mean that, somewhere, somehow, I have to add salt? If so, how much and how do I get to know when it's required? Perhaps that's a stupid question to someone who didn't fail their Chemistry exams, but I thought the salt came from the water and from the mains water that I fill it (periodically) with which, in my pueblo, is very salty anyway.
Oh! Dear. I think I'll have to go away on a course somewhere!
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White Horse
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Re: Pool chlorine/salt levels (again)

Postby White Horse » Sat Nov 04, 2017 12:36 am

There must be salt already in the water. You can get a test kit for the salt. It should be at about 3%. That is 30kg of salt per cubic metre of water. As your chlorinator is producing chlorine, there must be a healthy level of salt in the pool. You should just about be able to taste the salt. You should test it using a kit.


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