Pool has turned green and water is very old

[bisel]

I am writing for a friend. He recently added a product to his pool called "Pool Perfect". This is a magic elixir recommended by Leslie's Pool supply for $50 for 3 liters ... it is advertised that it helps break down oils, cosmetics and other organic material. Of course, for a guy who rarely swims in his pool one wonders why he thinks he needs such a product, but I digress.

Anyway, poor John adds a cup of the product to his pool and it instantly turns green and cloudy (see attachment). When he called me, my first question was when he last drained and re-filled his pool. John was unsure but believe it has been about 8 years. My advice was that he needs to drain his pool and get some fresh water in there as the water in his pool is subject to difficulty maintaining proper chemistry. My thought is that the addition of Pool Perfect probably did not actually cause the algae bloom. He probably would have experienced it in any case due to the condition of his water.

Now here in Arizona, the recommendation for plaster lined pools is drain the pool only when the ambient temperature is less than 85 deg F. otherwise the surface could crack. So here we are at the end of May and temperature will dip to less than 85 deg only at night.

My question for you all ... is there a way one can drain the pool and mitigate the possibility of cracking? Perhaps run a sprinkler on the pool surface while draining and filling to keep the pool liner surface wet?

Thanks for you help.

Steve

[Teapot1]

Sounds like you are trying to find away around what is commonly regarded as good advice, you can probably guess my response.
From pool perfects MSDS its a combination of flocculent ( poly aluminum chloride) and phoshate reducer (lanthanum salts). Phosphate reducers frequently make the water cloudy and flocculent could do similar as it flocs the compounds together. As you said the green was probably going to happen anyway.
I believe the water can be saved rather than thrown away and replaced and the savings from doing so can be used to improve the pools water treatment long term.

[bisel]

Quick update. My friend, John, has had a service come by and they have drained the pool. I expect all be well once it is filled and chemically balanced.

Steve

[bisel]

Sounds like you are trying to find away around what is commonly regarded as good advice, you can probably guess my response.
From pool perfects MSDS its a combination of flocculent ( poly aluminum chloride) and phosphate reducer (lanthanum salts). Phosphate reducers frequently make the water cloudy and flocculent could do similar as it flocs the compounds together. As you said the green was probably going to happen anyway.
I believe the water can be saved rather than thrown away and replaced and the savings from doing so can be used to improve the pools water treatment long term.

I had a similar situation a few years ago ... my pool was continually having algae growth and although I was shocking the pool and maintaining the chlorine level and pH, I continued getting algae. I went to the pool store and they sold me a bunch of magic elixirs to reduce phosphates, remove metal ions and whatnot. In the end, following advice I received here on the forum, I drained my pool and refilled it and then balanced the chemistry. All has been well since and I drain my pool every two years now. Nary a problem and all I do is to add a couple of pounds of CYA to the fresh water and then maintain the pH, put in chorine tabs with an occasional shock.

Refilling the pool costs around $150 or so. Not a bad amount to pay to have nice looking water.

Steve

[Denniswiseman]

Draining pools isn't always as simple especially if you have ground water

[Teapot1]

Refilling the pool costs around $150 or so. Not a bad amount to pay to have nice looking water.

Steve

Thats not too bad cost wise, many others have to spend considerably more. And the labour for the pool shop operatives?
As you said in your text, in the pool shop you bought special elixir. Most often not required so giving pool shops a wide birth is generally better, certainly for your bank balance.
The point I was making is improving the filtration and water treatment can avoid the costly drain and refil with the inherent risk of a pool failure. From the large amount of planting around your friends pool, phosphate could always be a problem. What is the quality of the new water? In some areas that too can be supplied already high in phosphate. Do the pool companies test after refilling? What type of filtration, how good is it? Generally the filtration is too small and the pump too large meaning that filtration is too rapid and slower filtration is better filtration. A variable speed pump would save a fortune running a pool of that size and perform better meaning better water quality.