Real-life case: back from holiday to a pea-soup pool
- The situation: 3 weeks away in summer, home to opaque green water, floor invisible.
- The difference from simple green water: this needs a reinforced shock THEN flocculation for the dead algae.
- Actual rescue time: 4 days to swimming — without draining.
- The lesson: holiday mode (scheduled filtration + long-life sanitiser + a neighbour who tests) prevents all of this.
Three weeks of August somewhere else, home on a Sunday evening. The suitcase isn’t even through the door when the verdict lands: the pool is dark-green soup, floor invisible, surface speckled with debris. It was predictable — the filtration timer left on its “usual” setting didn’t keep up with the heatwave, and the chlorine burned out within a fortnight. Here’s the complete rescue, day by day: longer than a fresh green pool, but with no draining and no miracles — just method.
Day 1: taking honest stock
Monday morning starts with what can be touched: net for the big debris, skimmer baskets, pump basket. Then a full brushing — miserable work in opaque water, but decisive. Photo test: chlorine at absolute zero, pH drifted high, stabiliser in the correct zone (a stroke of luck: previous shocks had used unstabilised chlorine). The app puts the water at the bottom of its score and proposes the “reinforced rescue” plan: the difference from simple green water is scale — a biomass like this demands a markedly higher shock concentration, and the dead algae will then have to be dealt with by flocculation.
Monday noon: pH corrected (calculated dose, re-test an hour later). Monday afternoon: reinforced shock, calibrated for the 38 m³ and the chemical void it was starting from. Continuous filtration launched — it won’t stop all week. Swimming: best avoided, obviously, and the app hammers the point home.
Days 2-3: from green to white, from white to haze
By Tuesday the water has turned milky grey-green: the algae are dying en masse. It’s the psychologically hard moment — “it’s worse than before!” — when it’s actually exactly the expected process. Filter cleaned morning and evening (the pressure climbs fast with that much matter), daily photo re-test: the chlorine is being consumed heavily, and the app recommends a calculated top-up to keep the pressure on what’s left.
By Wednesday the water is whitish, then hazy: no more living algae, but their remains are floating about, too fine for the sand filter. Flocculation step of the plan: the flocculant clumps the fines into flakes that sink overnight, with the filtration switched off at the end of the process to let everything settle.
Day 4: vacuum, re-test, verdict
Thursday morning, the floor is visible again — covered in a white-grey down of floc. Slow vacuuming straight to waste (sending that through the filter would clog it), water topped up to compensate, one last full re-test: pH in range, chlorine back down into the swimming zone, water crystal clear. The swim indicator flips back to “ideal” — four days after coming home, and three days ahead of what the overbooked local pool shop had quoted.
The lesson: holiday mode
This whole project came down to three precautions before leaving: filtration scheduled for the heat (not for the month of June), a properly sized long-life sanitiser, and a weekly photo test by a trusted neighbour — the app would have told them what to do at the first sign of drift. That’s exactly what the app’s holiday mode sets up: you leave with peace of mind, and the water waits for you the way you left it.
Frequently asked questions
Can water that's been opaque for weeks really be rescued without draining?
In the vast majority of cases, yes: it's a matter of the correct dose, flocculation and filtration. Draining is reserved for extreme cases — and carries its own structural risks.
Why one "reinforced" shock rather than two normal ones?
A large biomass demands a sufficient concentration in one go: successive half-doses let the algae recover in between, use more product overall and add stabiliser with every round.
How do I avoid this next holiday?
Three precautions: filtration on a timer set for the heat, a properly sized long-life sanitiser before leaving, and ideally someone who drops by for a weekly photo test — the app tells them what to do if things drift.