Run your filter long enough to turn the pool volume over at least once per day. For most residential pools:
Summer (Oct–Apr): 8–10 hours minimum
Winter (May–Sep): 4–6 hours
With a variable speed pump you can run at lower speed for longer and filter more water for less electricity. Overnight runs during off-peak tariff periods are ideal.
Most Perth pools need a partial drain and refill every 3–5 years. Over time, total dissolved solids, cyanuric acid, and calcium hardness build to levels that chemicals alone can't fix — only dilution with fresh water resolves it.
Signs it's time: persistent cloudiness despite correct chemistry, stabiliser above 100 ppm, TDS above 3,000 ppm, or water that just “looks tired”. A 50% partial drain is usually sufficient and is safer than a full drain for fibreglass pools.
Small top-up doses of chlorine or pH adjuster: wait 15–30 minutes with the pump running.
Shock treatment: wait until free chlorine drops below 5 ppm — usually 12–24 hours.
Algaecide: follow product label, usually 15–30 minutes.
Acid: wait at least 4 hours and retest pH before swimming.
When in doubt, wait and retest. Chlorine test strips are cheap and take 30 seconds.