One distinction sorts out most of this subject, and it is not the one people reach for.
Cloudy is not the same problem as green.
Green is something growing, and that is a sanitiser story. Cloudy is suspended material — fine particles held in the water, too small to settle and too small for the filter to have caught yet — and that is a filtration story.
Which means a pool can have faultless readings and still be cloudy, and adding more product to it will change nothing at all. That is the single most common wasted week we see in July.
Why A Hot Week Does This
Three demands go up at the same time, and the pool gets blamed for one of them.
Sunlight destroys sanitiser faster. A bright afternoon burns off free chlorine, so the reserve that held comfortably in June is gone by evening in a hot spell.
Warm water accelerates everything biological. What was present and dormant becomes active, and the pool's demand climbs for reasons that have nothing to do with how well it is being dosed.
And people actually use the pool. Bather load is the demand nobody counts, and it is the one that rises highest in a heat wave: sunscreen, skin, hair products, sweat, and everything that comes in on eight sets of feet.
All three arrive in the same week. The pool that was in perfect order on the Monday is behind by the Thursday, and it did not do anything wrong.
Which Kind Of Cloudy Have You Got
Look at it in daylight and answer two questions.
Can you see the bottom in the deep end, but everything looks slightly flat and dull rather than sharp? That is fine suspended material and it is a filtration and circulation question. The colour is basically right; the clarity is not.
Is there a colour to it — a green cast, a grey-green, a haze that is getting worse day on day? That is something growing, and it is a sanitiser question first. It will not be filtered clear while whatever is causing it is still multiplying.
A third case worth naming: water that clouded suddenly, within hours, usually after a shock or a rain event. That is often something that has come out of solution — the water was carrying more of something than it can hold at that temperature and pH. It behaves like a filtration problem and it has a chemistry cause, and it is exactly the case where a measured panel earns its money.
The Filtration Side, Which Is Where The Wins Are
Four things, and none of them is a product.
Run time. Sanitiser handles what is dissolved; the filter removes what is suspended. A pool cannot be filtered clear in hours it is not running. In a hot week with a full pool the schedule that was right in June is under-filtering, and extending run time is the first response to try and the one that costs least.
And if you have a variable-speed pump, look at the speed as well as the hours. The whole economy of those pumps is running slowly for long periods, which is genuinely better filtration per unit of electricity — but a slow speed that was ample in June can be short of what a hot week with heavy use needs. This is the thing owners of new pumps most often miss, because the pump is not faulty and the settings are not wrong; they are simply the June settings. See variable-speed pool pumps.
Filter pressure, against its clean pressure. The number alone means nothing; the difference from where that filter sits clean means everything. A filter that has drifted up and does not come back after a backwash is restricting flow, and restricted flow in a heat wave is the difference between a pool that recovers and one that does not. See pool filter repair and, for how the media types differ, filter media compared.
Baskets, both of them. Skimmer and pump. A full basket in July is the most common cause of poor flow on any pool, and it is free to fix.
What We Do Not Do About Cloudy Water
Said plainly, because the obvious answers are outside our scope.
We do not vacuum, brush or skim pools — not in a heat wave and not as a weekly service. And we do not vacuum to waste, which is the specific thing people ask for on a cloudy pool. Our work is water chemistry, baskets, filtration and equipment; surfaces and manual clearing are the robot's job or yours.
We do not offer leak detection. A pool that is both cloudy and losing water has two problems, and the second one is a specialist service and not one of ours.
And we are not going to publish doses. What a pool needs depends on its volume, its current panel and its stabiliser level, and a number on a web page is how people end up correcting the wrong thing twice.
What Actually Fixes It
In order, and the order is the point.
1. Measure, do not guess. A full panel by titration — a drop test resolves a number, a strip gives you a colour and an impression. On cloudy water the reading that matters most is often the one home kits do not do: the difference between sanitiser that is available and sanitiser that has already reacted and is doing nothing.
2. Correct in sequence, not all at once. Alkalinity before pH, stabiliser established before anyone judges a chlorine reading. Out of order and every correction gets re-made. The full sequence is on early-season chemistry — it is the same logic in July, applied to a pool that is behind rather than starting.
3. Then filter, for longer than feels necessary. Once the chemistry is right, clarity is time and flow. A pool that has been cloudy for a week does not clear in an evening, because everything in suspension has to physically pass through the filter and be caught.
4. And take the load off while it recovers. Fewer swimmers for a day or two. Unwelcome in July, and it shortens the recovery more than anything else on this list.
The Version Where July Is Uneventful
Every heat wave above is survivable and the difference is what the pool was like going into it.
A pool carrying a good sanitiser reserve, correct alkalinity, a known stabiliser level and a filter at its clean pressure absorbs a hot week. A pool that was already slightly behind does not — and "slightly behind" is invisible from the deck.
Which is what regularity buys, rather than intensity. A chemical and equipment check is from $72 per visit plus chemicals, with a written sheet every visit. In a hot summer the sheet is doing something specific: a demand that climbs three weeks running, or a filter pressure that never quite returns, is visible across sheets and invisible in any single visit — and both are exactly what turns a heat wave into a cloudy fortnight.
Where the water will not clear whatever the numbers say, something on the pad is wrong rather than unbalanced. A $150 service call covers up to the first hour of diagnosis on site, with parts and further labour quoted first. See pool equipment repair.
See weekly pool service for the regular version.
