Green pool recovery in Pakenham & Cardinia Shire.

1. Day 1 — assess + shock: we test the water (pH, chlorine, alkalinity, phosphate, algae type). Brush the walls and floor to break the algae film off. Heavy shock dose — usually 4–6 times normal chlorine, with pH dropped to 7.2 first so the chlorine actually works. Pump and filter running 24/7 from that point.
2. Day 2–4 — dead algae clears: water shifts from green to milky white-grey as the algae dies. We come back at day 2 to test residual chlorine, check filter pressure, backwash or clean the filter (often twice a day on a heavy bloom), top up the shock if residual has dropped.
3. Day 4–6 — manual vacuum to waste: dead algae settles on the floor as a grey sludge. We vacuum to waste (bypassing the filter, water goes straight out the backwash line) so the sludge doesn’t re-circulate. Top up the pool with fresh water as we go.
4. Day 6–8 — rebalance: water is now clear but chemistry is off — chlorine high, pH off, alkalinity probably low. Full rebalance to bring pH, alkalinity, calcium, stabiliser and salt back to spec.
5. Day 10–14 — recheck + handover: one more visit to confirm chemistry has settled, the algae is gone, and the filter is back to normal pressure. From here, regular fortnightly servicing keeps it from happening again.

Cost breakdown.

• Mild green / cloudy (24–48h to clear): $250–$350 single visit + 1 follow-up
• Standard swamp-green (5–7 days): $350–$500 callout + 2–3 balancing visits ($120–$200)
• Heavy / black-green algae (7–10 days): $500–$600 callout + 3 balancing visits ($150–$240), filter media may need replacing ($150–$400 extra)
• Cell or pump replacement needed during recovery: quoted on top — usually $350–$1,500 depending on part

Why we don’t just “dump a bag of shock in”.

Bunnings will sell you a $40 bag of pool shock with instructions to tip it in. That works in maybe 1 of 5 cases. Most green pools fail a DIY shock because: pH is too high so the shock chlorine can’t sanitise, stabiliser is wrong so the chlorine disappears overnight, the filter is too clogged to clear the dead algae, or phosphate levels are sky-high feeding the next bloom. The recovery is half chemistry, half mechanical — doing one without the other wastes the chemicals.

After-recovery: keep it from coming back.

Every recovery includes a written diagnosis of why the pool went green — cell failure, low stabiliser, pump dropout, fertiliser run-off, whatever it was. The fix is either a one-off equipment job or a switch to a tighter service cadence (or both). Clients on regular fortnightly servicing after a green-pool recovery have a near-zero repeat rate.