Sudden Onset Greening and Cloudiness

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Casscat
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Sudden Onset Greening and Cloudiness

Post by Casscat »

Never happened before. All pool testing absolutely spot on, but the water has suddenly decided to emulate the Olympic diving pool and take on a greenish and slightly cloudy appearance. My man on the spot says that this has happened to several local pools recently so it must be a local weather/atmospheric phenomenon so a) what is causing it and b) more importantly how do I treat it? I have guests in residence (arrived yesterday) so massive, toxic chemical overload might be hard to introduce. Advice please :(
Annew
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Post by Annew »

Has happened a couple of times in 15 years to our indoor pool - double backwash, shock treatment and chlorine balance usually helps, but I expect you would need to consult your pool chemical suppliers or maintenance people for accurate advice.

According to Mr AnneW (resident pool boy) apparently, green is usually caused by a bloom of algae in the filtration system of our indoor pool and I guess it's the same for an outdoor pool. Our pool maintenance guy has no idea what the catalyst is with our indoor pool, but he suspects its to do with ambient temperature in the plant room and he advised us that it does just happen from time to time.

Usually takes about 6 hours or so to clear and shocking the pool should not affect your guests if you close the pool daily
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Casscat
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Post by Casscat »

Thank you :) I hope my guy there can resolve it as I feel terrible for my guests. It's not hideously unsightly, but I know how crystal clear it should be and it's patently not right now :(
COYS
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Post by COYS »

No expert, but it points to a chemical imbalance that better knowledge than mine may impart. Not always cured by shocking/algicides etc.
A recent & basic training course has improved my personal knowledge but did surprise me somewhat in regard of the de- facto pool care we personally receive.
To be clear, that's a regional issue for us & there are far greater minds than mine in this field.
Response posted as we face similar problems at least annually. A maintenance issue or just a natural phenomenon?
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Mouse
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Post by Mouse »

We had this last year....in August. It was an exceptionally hot year and that combined with the suncream overload (we had a lot of kids who parents always seem to slather in cream) caused cloudiness and greening.
I don't know what he did but our pool guy sorted it within a day.....we had to leave the jets on for 24hrs.

As an aside; we've just bought a miracle product from the pool shop that clears pools almost instantly.....its called Clean Pool PM663 by Piscimar. So might be worthwhile your pool man talking to your local shop if he can't clear it. It's 16 tabs for 15 euros (but may be cheaper elsewhere as ibiza is expensive). We were advised to put 1 tab into each skimmer. You use it when it starts to cloud.

Mouse
x
p.s. whilst we were fretting our guests didn't think there was anything wrong so don't worry too much
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teapot
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Post by teapot »

It's quite normal to get two algae blooms per year. If the water is high in nutrients like phosphates it becomes really easy for the algae to take over.
Poor quality filtration and low sanitiser is easily the biggest cause.
When people say my tests show normal, that isn't the whole story. One of the biggest factors is the cyanuric acid (stabiliser) level. All pre packed pool chemicals apart from HTH choc contain stabiliser and the best way to tell is to look at the back of the packet it will describe the contents as Trichlo or Dichlor isocyanurates and that is the stabiliser

You need to be able to test the CYA (stabiliser) level 30-50ppm is ok but those using galetts over and over can reach levels of 100-200ppm so you don't then despite the tester saying normal have enough free active chlorine to keep the pool clear.

I have CYA testers if you can't find them in France.

Mouse that product is a clarifyer based on Jolly jelly/Miraclear etc. Yes it improve the filtration and can help to lower phosphate levels but the better way is with improved filtration in the first place. I also have some Miraclear left but back over to france in the morning so out of contact for a day or so.
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Mas Nialgue
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Post by Mas Nialgue »

I treat with peroxide 35% sold here as Blue Top rather than chlore shock.

The advantage is that the pool can be used 2 hours after treatment (Chlore shock 24 hours) and normally the pool is clear again after 24 hours.

Only thing is it will nullify your test readings for 10 days, so adjust PH before treatment and test again after 10 days.
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Post by Zorba »

I have posed this before - Cyprus is quite a bit hotter than the rest of Europe and when the water gets over 30C ~ 33C my experience this can happen.

Chlorine lock as Teapot describes can be the cause but presumably your pool man has done a check. I disagree with him that levels over 50ppm will cause this. 50ppm is the ideal maximum but I have seen many private pools with levels over 100pm that remain clear. (The Rio pool was almost certainly chlorine lock as the water was reportedly new. I guess like most commercial pools they used un-stabilised chlorine and added the cyanuric acid separately. Someone may well have miscalculated the dose and got the decimal point wrong in his calculations.)

I keep our Cyanuric Acid levels down by using on alternate doses trichlor granules (which does contain the cyanuric acid) but is acid in nature and Calcium hypochlorite granules which has none but is alkali in nature. Never ever mix them in the same bucket or skimmer as different types of chlorine react with each other in an undiluted state. Using two types of granular chlorine avoids much of the PH adjustment. I have a personal dislike for all dichlor and trichlor tablets as the release of chlorine is too slow and difficult to regulate and the cyanuric acid that comes included of course.)

I have also found that leaves from certain trees like the mulberry tree and any contamination like sucking back very small quantities of earth from a faulty skimmer or pipe when the pump is off increases the nutrients and certainly can be the route cause of a bloom.

In your circumatances I would treat with "Silvertrine" or "HTH total blackshock" and keep the pump running for 3 days and then backwash. The pool can be used after an hour or two, so no need to close it -once it is clear.
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teapot
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Post by teapot »

Mas Nialgue wrote:I treat with peroxide 35% sold here as Blue Top rather than chlore shock.

The advantage is that the pool can be used 2 hours after treatment (Chlore shock 24 hours) and normally the pool is clear again after 24 hours.

Only thing is it will nullify your test readings for 10 days, so adjust PH before treatment and test again after 10 days.
I would just like to add that shocking a pool is a process and NOT a product, they should be labelled fast dissolving chlorine.

Using hydrogen peroxide costs 3+ times as much as chlorine €75 ish.
Hydrogen peroxide is a stronger oxidiser than chlorine but a worse sanitiser.
Hydrogen peroxide doesn't nullify your test readings, your pool will test zero chlorine because the hydrogen peroxide has burned out all the chlorine (oxidised) and it will take additional chlorine after the peroxide has broken down to get things back to how they should be. You can still swim in a chlorine choc'd pool but better to not let it go green in the first place.
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teapot
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Post by teapot »

Zorba wrote:I disagree with him that levels over 50ppm will cause this. 50ppm is the ideal maximum but I have seen many private pools with levels over 100pm that remain clear.
I am not sure I actually said that, The suggested levels of stabiliser are between 30-50ppm, several salt chlorine manufacturers recommend 70ppm, presumably to protect the plates from the hyperchlorous acid.

There is no such thing as chlorine lock, only insufficient free active chlorine for the level of stabiliser present.

As to presuming the pool person has checked the level, that would be wishful thinking in most cases and DIP strips are hopeless for checking stabiliser levels.

If the nutrient levels are low in a pool then algae are slow to grow, I have seen and tested pools running 180 & 200 ppm of stabiliser staying clear until one morning, Oops it's gone green. Then with that level of stabiliser the amount of chlorine required to chock the pool is just not added by normal people (80ppm of chlorine) so at that point the process of dumping stupid levels of algaecide into the pool causing a foaming mess and further using up more chlorine to oxidise the algaecide.

As more desperation sets in with guests arriving in 48 hours or less anything vaguely hopeful like peroxide et al gets dumped into the pool.

I have a lovely video of this on my old phone, I will have to see if I can post it on here.

Buying an auto doser, using eau de javel (chlorine bleach) instead of packaged products, having a decent tester and the smallest grasp of pool chemistry and pool management is so much easier.

I would propose that the Rio pool was unstabilised chlorine, they forgot the stabiliser and all of their chlorine was destroyed by the strong Rio sun in under two hours leaving the slightly iffy Rio water to turn green very quickly.
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cleanforum
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Post by cleanforum »

Yes, asuming you have the ph and clorine levels correct then, check the stabilizer as mentioned above.

Very important this as cheaper chlorine tabs often dont have it so your chlorine will tend to evaporate or not be released as mentioned above.

Meanwhile a shock with chlorine granules should get your pool colour back to blue at least.
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teapot
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Post by teapot »

cleanforum wrote:
Very important this as cheaper chlorine tabs often dont have it so your chlorine will tend to evaporate or not be released as mentioned above.

Meanwhile a shock with chlorine granules should get your pool colour back to blue at least.
I am afraid that is quite incorrect, the cheaper chlorine tabs have the same amount of stabiliser compared the more expensive ones.
Cheaper ones are Dichlor (2 molecules of chlorine, the rest is stabiliser) more expensive ones are Trichlor which gives 33% more chlorine for the equivalent weight so doubtful if they are really any cheaper.

If you continue to shock with granulated chlorine on a pool that is already over stabilised you just make things worse still. better to use an un-stabilised form like liquid chlorine.
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cleanforum
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Post by cleanforum »

Depends where you are then. here in Malaga I can assure you that I have been passed a large batch of cheap chlorine tablets that have absolutly NO or very little stabilizer at all. Nada. I had to buy and add some stabalizer to reach the required level. Since then the pool has been fine.

"It's quite normal to get two algae blooms per year"

Disagree with that, from my experience (20 years with various pools) with the water & climate we have here in my particular zone of Malaga. Blooms only occured when one of more of the water chemistry factors went off limits.
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teapot
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Post by teapot »

cleanforum wrote:Depends where you are then. here in Malaga I can assure you that I have been passed a large batch of cheap chlorine tablets that have absolutly NO or very little stabilizer at all. Nada. I had to buy and add some stabalizer to reach the required level. Since then the pool has been fine.

"It's quite normal to get two algae blooms per year"

Disagree with that, from my experience (20 years with various pools) with the water & climate we have here in my particular zone of Malaga. Blooms only occured when one of more of the water chemistry factors went off limits.
Cleanforum, I do not really believe it's down to where you are. There are only really 3 common packaged forms of pool chlorine, leaving out lithium hypochlorite.
The easiest way to answer your point is if you read the back of the package of your cheap chlorine and report back. Chlorine would dissolve immediately on contact with water if it is not bound to another slower dissolving compound, Usually this is the stabiliser cyanuric acid and so we get trichloroisocyanuric acid (trichlor) or the cheaper dichloroisocyanuric acid (dichlor) as described above. The third version that doesn't contain any stabiliser is calcium hypochlorite, which as the name suggests uses calcium as the binder. With Cal hypo you introduce more calcium which in hard water areas or over time could cause scale on the pool surfaces. It is very important that cal hypo is not mixed with trichlor or dichlor, they can be used in the same pools but must not come into contact with each other. Cal hypo is usually marketed by HTH Lorenzo chemicals branding.

By two blooms I meant by natural timing, spring and mid August. As you say if the pool water is well filtered, kept moving and water parameters and sanitiser levels correct you do not need to be affected by any of the algae problems that beset others. High stabiliser levels, poor water movement and an excess of nutrients (nitrates and phosphates) can all lead to issues. It's popular around this time for pool to be uncovered and waterline marks to be cleaned. a lot of cleaners are phosphate based so adding a lot of algae food to the mix, don't over look phosphate removers.
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