bridie

...yet again our pool is green?!

Dont know why, yesterday it was clear as a bell, just added some salt and noticed it's got a green tinge to it... cant add chlorine or run the filter until the salt is dissolved.

Can anyone tell me in easy steps what I should be doing to make sure this doesnt happen again? I added some chlorine about 2 or 3 weeks ago... how often should I need to add it?

Thanks

worzel

On bore water? That will increase the likelihood of phosphates although it shouldn't really be a problem this early in the year when water tables are high. When we had that it took - shock treatment, salt, acid and stabiliser from memory. I highly recommend taking a sample to the pool shop Bridie.

EvannTel

Hi Bridie
Salt is not the answer per se. If you have enough salt in the system, it stays there - the pool is a closed system. Salt is only lost through splashing out of the pool and backwashing. If you have done this and topped up you may need salt.
Chlorine demand is higher here now with the sudden increase in heat - you will need to run the chlorinator for longer periods to maintain chlorine levels.
Also we had similar problem a few weeks and had to shock the system - this means adding liquid chlorine to the pool to bring chloirne levels up to between 5 and 10ppm - bright hot pink on your test.
Is you pH ok? This can affect chlorine loss of too low. Have you enough alkalinity - again your test kit can tell you this.
Finally a factor can be the isocyanuric acid levels need to be high enough to stabilise the chlorine - otherwise when hot like now it'll last 5 minutes. Its rare this needs doing though (we've never done our in 18 months).

If you want give give a Terri a call and I can pop round or talk to you on the phone (being a chemist I'm anal about my pool chemistry - more than needs be!)

EvannTel

We also had phosate problems (previous oweners using bore water) but this was earlier in the year and you can easily remove with lanthimum carbonate. Good advice but like you I;d say unlikely.

worzel

It sounds like you may know more than our pool shop! But we were told if you get phosphates in the pool it "eats" the salt. So, I was told, first you need to recover with shock treatment, then add salt to create that ongoing healthy system.

EvannTel

Shock treatment will not get rid of phosphates, no way ever. Its surprising advice as the Lanthanum additive for phosphates is expensive - you'd think that would be first recommendation!

Get rid of phosphates, check salt levels, shock to clear pool and away you go.

One other thing for Bridie is to check her cell isn't all scaled up as this will effect performance - usually he control unit warning light will come on wrn of this though.

worzel

Okay, maybe there was something else first before my list of stuff. It was nearly two years ago we had the problem and the pool is a job I happily delegated to the wife!

datamile

Just take a sample to the pool shop. Have you added stabliser this year as that will completely bugger your chlorine levels if you've got too little or too much.

As above check your chlorinator is not blocked with white stuff.

phosate is a pig, but you add phosate remover, leave for an hour or so, and then vac and flush to get rid of some of it.

jackhigh

sounds like your chlorinator could be on its way out. If you have the correct amount of salt in your water, you're running your filter/chlorinator for about
6 - 8 hours a day and its (chlorinator) is working efficiently, you shouldn't be needing to add chlorine. Check the cell to make sure its not caked up, if it is clean it with a proprietary cell cleaner(some use one part acid to 10 parts water to clean cells but not recommended). Really though it could be a number of different things, insufficient chlorine, no stabiliser (uv sunscreen) too much salt if you've just added some and your salt levels were already sufficient or you may have a touch of algae.
Like already mentioned, get a water sample down to your local pool shop. They will test the water for you, usually free and advise on treatment. They will also be able to quickly test your chlorinator if they suspect that it is not working properly.

steveyp

I wish more of my shop customers were as informed as some of you!

one, two, three or four problems possibly here..

1. pH level too high, high pH reduces production of hypochlorous acid from chlorine, this is the compound that dissinfects your pool. Chlorine is half as effective at pH of 8 than at 7.5.
2. Phosphates are food for algea, we often see green pools with perfect water balance. For very high levels use a floculant first and vacuum to waste. then a lanthium based chemical e.g starver to lower levels progressively over 2 weeks.
3. Water temperature over 28C causes excessive chlorine use.
4. High TDS - total dissolved solids - I have seen stubborn algea blooms in pools with good water balance and no phosphates with TDS readings in excess of 10,000 ppm. Older water can be high as water evaporates and leaves the solids behind... hence solids accumulate. These charges particles can prevent the chemical reactions chlorines needs to oxidise waste. Can also cause scaling.

Always use a copper based algecide year round, this will penetrate the algea cell and kill it, especially useful for black and mustard algae.

Takes you sample to the shop and don't settle for a 'don't know'
And if you do need a new chlorinator, I will sell you one at a fantastic price!

datamile

Can agree with the hot water.. my pool is solar heated to 31C this year, and it's really buggering the chlorine levels.

Pool chemistry is a fun game of gently do it, or it'll be yo-yoing around all season.

EvannTel

Amen to that

moneypenny20

Also it's worth taking a sample to more than one shop. They are not all lovely, reliable people, some - shock horror - are simply out for how much money they can get out of you If you get the same story and are being asked to buy the same stuff, you're fine, if one tries to sell you stacks of different stuff and baffle you with science, be wary.

Print off the advice given here and make out you know what you're (sort of) talking about.

JackTheLad

Do you mean phosphate? Or do they have a slang term for it here in Oz?

JTL

datamile

No, phosate is my pig , and sometimes he jumps in the pool.