Cloudy swimming pool - anything I can do to help OH?

I realise this topic has been covered before, so apologies for bringing it up again.
I’ve been trawling through the swimming pool section looking for advice. Unfortunately I know little or nothing about our pool so much of the info is going way over my head, but OH is in UK for a week and I’m left in charge (oh help!) with instructions on how to clean pool.
Unfortunately this year the pool is cloudy and we have guests here so I’m wondering if I can do anything simple to improve the situation?
The cloudiness was due to algae because I think we weren’t running the pool pump for long enough as the temperature went up quite quickly and we took our eye off the ball.
OH bought some “clarificant” from Lidl which is supposed to precipitate out the algae. We now have a fine layer on the pool bottom which precipitated out overnight but it is too fine to hoover up and just seems to swirl back up into the pool.
He has backwashed several times and hoovered several times but there is still some fine sediment there.
There are two flocculant tabs in the skimmer basket which the shop recommended (though I note that there is some view that flocculant is not a good idea).
I will hoover very carefully each morning.
I’ll run the pool pump continuously for 15 hours (in fact the pool temperature has dropped to the mid 20s because of adding more cold water after backwashing)
I’m also wondering whether, if I add liquid bleach, will that help? We have a salt pool and the reading on the meter is 7, which I understand is ok.
Is there anything else I can do, bearing in mind I am a TOTAL novice at this and so it needs to be simple and may not be a total solution but might improve things for when OH is back?
Thanks for any thoughts.
By the way, our pool is 4X8 meters and has one skimmer and two pushers and a borne de fonde and a sand filter and is a salt pool.

Persevere, the flocculated stuff should eventually be taken out by the vacuum/ filter and backwashed away. I would try to independently verify your chlorine and pH (and stabiliser) levels using colorimetrictests. The salt is just electrolysed to release chlorine into the pool.

Had a similar issue once when using (supposedly calibrated) electronic testers, they were miles out

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How do you vacuum Sue?
I agree, some water test results are needed. Nothing wrong with flocculent unless its DE or cartridge filter.

Using a hose that is fitted into the skimmer and I just move the brush slowly and carefully across the floor of the pool.

Thanks for your suggestion @Mark and @Corona

Test results - all OH has is test bandelettes, which don’t seem a very exact science, so, I’ve just done it and so far as I can tell:

Alcalinite: It’s a pale green - somewhere between 40-80 I’d guess

pH: mid pink, 7.2-7.5 at a guess

Acide cyanurique: palish yellow, which seems to be off the scale as the lowest colour is slightly pink orange

Chlore libre: white, which could be 1 or 0

Chlore Total (Brome Total) Greyish, between 5 (10) and 10(20) I reckon

Durete totale: Pale mauve - paler than the mauve on the bottle, so not sure if that’s between 250 and 500 or not.

Hope this makes sense. Thanks for your help

Ok Sue, the vacuum into the skimmer, is that with the skimmer basket in place and via a plate adapter?
Sounds like your chlorine is low and possibly the CYA although its anyones guess with dip strips as you say. Add some more chlorine for now.

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Thanks @Corona.
The skimmer basket comes out and there is a hole underneath into which the end of the hose fits.

Is there something better I could get him that would give him more accurate readings?

Do I use ordinary household bleach and if so, how much?

For testing, you need something like this

Test strips are very inaccurate

Something similar should be available at your local brico, either using tablets or liquid drops (DPD1 for chlorine and phenol red for pH)

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Hi Sue, ideally you would have a vacuum plate specific to your skimmer that allows you to retain the skimmer basket and vacuum then you can use the netskim socks inside the skimmer basket and in your case of fine debris you could scrunch up a cotton towel in the basket to collect the fine particles.

I used to supply the Certikin iris plate as the outside could be cut down to fit most skimmers. I often did tis with an electric belt sander but cut away the excess if it needed a lot removing


If you can get some brico eau de javel, 9.6%, 20lts or in 5lts if the former are too heavy. For your pool 450ml should give you about 1ppm so 900ml = 2ppm and so on.

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You also need a chlorine stabilser test (cyanuric acid, CYA ) tester as this is the most important test. It sets how much chlorine you need to adequately sanitise the water and avoid algae. Total chlorine DPD4 is another test worth having as it allows you to spot things begining to go wrong before it gets bad. For a vinyl lined pool hardness is pretty irrelevant but Alkalinty is useful, especially for salt chlorinated pools.

Morning Corona, thanks very much for your replies.

Our pool is over 30 years old - not sure things like that were around in those days? So are you saying that I can get one that fits our skimmer basket and that I should be vacuuming through the basket and the sock? OH certainly uses the netskim socks. I like the idea of the cotton towel. :grin:

I think I need to talk to OH about what he needs in the way of testing kits. When we first bought the house the pool behaved so beautifully none of this seemed necessary.

I really believe that is why many dont purchase good test kits. Pool companies who care more about profit dont supply them or dont understand water chemistry. As the water gets a bit older the biild up of organics and non organics increases leading to issues do good testing is more important. Things like servicing the sand filter often do not happen and domestic filters do not backwash very well so fine silt builds up in the media. Thats more hiding places for bacteria biofilm so issues suddenly happen where they didnt before.

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and be patient. My pool always takes a few days to clear after winter - but it always does clear.
As long as all else is well apart from the cloudiness, tell your guests it’s safe to swim in, and will clear in a day or two (or a few - depending on how cloudy).

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Relaying on the sand filter and backwash to clear the sediment will take forever. When hoovering set the sand filter control to waste which will bypass the filter and sediment will be pumped out of the system. You will need to keep topping up the pool with fresh water.


Our pool has two Hayward skimmers of a similar vintage to yours and I’ve not found a skimmer plate that fits/seals properly, so I simply remove the basket and plug the hose into one of the two holes underneath.

I find closing the valves on the suction side of the pump for the other skimmer and the sump as much as possible without casing the pump to lose prime improves the suction and limits the amount of water that goes to waste.

I also have a valve on my waste line to limit flow as I have an insane 25 cubic metre/hour pump.


Now that’s a really good idea! - Especially as I actually have a spare valve!

I find it doubly useful as I have a very slight leak to waste sometimes. I suspect some debris in the multiport valve has nicked the spider gasket I replaced a few years ago.

I highly recommend a manometer on both sand filter and multiport valve to keep an eye on system pressures if you like to adjust suction and return/waste valves during vacuuming as I do.

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Yes they clear eventually, thats shows the difference between good hydraulics and filtration and bad. Magiline, Desjoyaux and Waterair with their patented wacko strainers ( cant call them filters) can take weeks whereas a good system takes day(s). Running the filtration 24 hours helps as even passing the water through the filter 4 times is only around 90% of the water filteted because the filtered water returning to the pool is mixing with the dirty water once again, known as the law of dilution (Gage-Bidwell) if the filter media cannot trap the particles then it takes even longer. Slower filtration is better filtration as it captures more. Save time and money. Switching from sand which catches at best 20 micron particles to Dryden Aqua’s AFM glass media brings this down to 4-5 micron particle capture and the latest AFM ng (new generation) down to 1 micron particle capture and this is without flocculent, sub micron if flocvulent is used.


there were some early ones that had huge openings and baskets, is that what you have? Diameter?

I would recommend a variable speed drive, you may get that flow on vac to waste but not on filtration. What is the pressure on the filter gauges when filtering on a clean backwashed filter?

Main drains do very little, just weaken the action of the skimmers in most cases. Unless you manually push dirt into them its really a waste of electricity. Dirt enters from the top so that is the best place to remove it before it sinks.

I’d welcome some more thoughts please.
If the pool water is any better it is only marginal. Still very murky greenish colour.
I’ve put two white cotton face cloths in the skimmer and they are going a reassuring yellow colour (hopefully Sahara dust, or something).

I’ve now checked the pool house and discovered that OH bought some large white tablets from Briconautes called Force 5 250 Desinfection reguliere. desinfectant / antialgue / Tampon pH / Floculant / clarificant. There are two of them in the skimmer basket. All sorts of dire warnings about not using them with anything else and beware getting in eyes and killing fish - seems to me to be primarily slow release chlorine - the tablets last about 8 days apparently.
Perhaps I shouldn’t but I put another flocculant “cartouche” in the basket as well.
There is also a sack of sel +stabilisant tablets in the pool house which he chucks into the pool from time to time (to be used in our salt water pool.
I have bought some more cartouches this morning and stabilisant chlore from Briconautes.
I have not cleaned or backwashed today and I have kept the pool covered as the air temperature has dropped from 33 to just over 20 and our guests have gone out for the day. (Looks like the daytime air temperature is likely to stay at low 20s for rest of week, which means the pool water is currently warmer than the air.)
I am running the pool pump for 14 hours constantly.
Is there anything more I could be doing over the next 3 days before OH gets back to help improve things?

As always, really grateful for any thoughts/suggestions.