DIY Green Pool Recovery

Woke up to a swamp? You can rescue it yourself—safely and quickly—by following a precise sequence of steps. Here’s Pool Life’s step-by-step plan, geared for DIYers who want fast, reliable results without wasting chemicals.

Before you start your green pool recovery: safety & shopping list

Safety: Wear gloves and eye protection. Keep chemicals cool, dry, and separate (especially acid and chlorine). Add acid to water, never water to acid. Switch the equipment off at the isolator before opening anything.

Tools & supplies:

• Drop-test kit or photometer (FC, pH, TA, CH, CYA; salt if applicable)
• Liquid chlorine (sodium hypochlorite) for shocking
• Pool acid (to set pH)
• Stiff algae brush (concrete) or soft brush (fibreglass/vinyl)
• Leaf rake, manual vacuum & hose (even if you own a robot)
• Clarifier or flocculant (not both)
• Filter cleaner; spare skimmer/pump baskets

The Pool Life “green-to-clean” sequence

1) Restore circulation (10–15 min)

• Scoop out leaves and debris first (don’t let them rot).
• Empty skimmer and pump baskets; set the water level 2/3 up the skimmer mouth.
• Prime the pump so the lid fills (no air).

Why: Chemicals only work if water moves.

2) Set pH to ~7.2 (5–10 min + mix time)

• Test. If pH is high, add small doses of acid with the pump running.
• Circulate 30–60 minutes, then retest.

Why: Chlorine kills more effectively at lower pH levels (within the safe range).

3) Choose your shock level (based on CYA)

4) Brush like you mean it (10–20 min)

• Brush walls, steps, benches, behind ladders and lights, and the waterline.
• Expect the water to go from green to grey/teal as algae breaks up—that’s good.

5) Filter 24/7 and watch pressure (Day 1–2)

• Run the pump continuously during recovery.
• Backwash sand/DE when pressure rises 8–10 psi above clean.
• Cartridge filters: Hose elements when pressure increases or flow drops.
• Keep testing FC; top up to the shock level whenever it falls.

Goal: Hold shock level until algae is dead, not just faded.

6) Clear the clouds (pick one)

• Clarifier (easy mode): Helps the filter grab fine particles. Keep filtering; clean the filter as it clogs.
• Floc (fast mode): For heavy muck or a deadline. Dose, turn the pump off overnight, let particles settle, then vacuum to waste the next day (slowly). Top up water and rebalance.

Don’t use clarifier and floc together. Avoid running floc through cartridge/DE elements.

7) Rebalance once it’s blue but hazy

Correct, in this order:

1. TA (buffer)
2. pH (aim 7.2–7.6)
3. CH
4. CYA (don’t overshoot; tablets add CYA)
5. FC (return to normal range)

For salt pools, confirm salinity is within your chlorinator’s spec and clean the cell if scaled.

What a typical timeline looks like

• Day 0: Green → teal after shock + brush.
• Day 1: Cloudy blue/grey; filter working hard; maintain shock level.
• Day 2–3: Visible clearing; fine silt collects on the floor; resume normal FC once algae is dead.
• Day 3–5: “Polish” phase—go from clear to sparkling.

(Severe blooms, undersized/dirty filters, or very high CYA can extend this.)

Troubleshooting & special cases

• Brown tint after shocking: Likely metals (iron). Add a metal sequestrant, keep pH steady, and avoid large chlorine spikes until metals are bound.
• Mustard/yellow algae: Likes shady walls and returns. After clearing, hold FC at the high end for 24–48 hours, brush daily, and expose toys/brushes/robots/swimsuits to chlorinated water or sunlight.
• Black spot (plaster): Very stubborn. Use a stainless brush, targeted treatments, and sustained high FC over weeks.
• Strong “chlorine smell” / irritated eyes: Usually chloramines, not “too much chlorine.” Maintain shock level and improve circulation.

Common mistakes (and how to avoid them)

• Big chemical dumps: Overshooting wastes money and time. Dose in stages; retest between.
• Chasing pH before fixing TA: Set TA first so pH holds.
• Relying on the salt cell to shock: Use liquid chlorine for recovery; then let the SWG maintain the water once it is clear.
• Too little filtration: Run longer on low speed; clean/backwash as soon as pressure rises.
• Skipping brushing: It breaks biofilm so chlorine can finish the job.

Keep it from coming back.

• Match FC to CYA; don’t let stabiliser creep excessively high.
• Extend run time in hot, sunny weather.
• Brush weekly—it’s the cheapest algaecide.
• Scoop leaves early; consider phosphate remover if you have heavy organic loads and recurring blooms.
• Log tests and doses—you’ll spot trends before problems show.