Coming home from a couple of weeks away to a swamp instead of a swimming pool is one of the most common calls we get. The good news: green doesn't mean ruined. It almost always means your sanitiser dropped too low for too long and algae took the opportunity to move in.
It's almost never one big thing — it's usually a combination: chlorine or salt levels drifted down (often from a hot spell increasing demand, or the chlorinator/pump being switched off while you were away), warm water gave algae the conditions it needed, and once it takes hold, algae multiplies fast enough to cloud a whole pool within days.
Most residential pools clear up within 2–4 days once we start treatment, though very dark "pea soup" pools can take a little longer. Either way, it's almost always faster and cheaper than most people expect — and a lot less painful than draining and refilling.
Yes — the fix is usually simple: keep a consistent chemical balance running even while you're away (a service visit scheduled for while you're on holidays does the job), and make sure your chlorinator or salt system isn't switched off at the wall by accident.
Staring at a green pool right now? Get a recovery quote — we can usually get started within the week.