The Best Way to Clean a Pool: A Fibreglass Routine
The best way to clean a pool is a steady weekly routine: skim, brush the gelcoat safely, vacuum and check the water. Here's the method for fibreglass pools.
The best way to clean a pool is a short weekly routine you actually stick to, not a big rescue every time the water turns green. Skim the surface, brush the walls, vacuum the floor and check the water chemistry once a week, and a fibreglass pool stays clear with a fraction of the effort. Let it slide for a fortnight and you're suddenly scrubbing algae off the waterline and dumping in chemicals to catch up.
Fibreglass makes this easier than most surfaces. The gelcoat is smooth and non-porous, so there's nowhere for algae to take hold the way it does in the rough pores of concrete. That single property is why fibreglass pool cleaning is genuinely light work — as long as you match your tools to the surface and keep to a rhythm.
Skim the surface every day it's used
Skim floating debris the moment it lands, because anything you catch on the surface never sinks to become a vacuuming job later. A hand skimmer net by the poolside is a pool owner's best weapon against leaves, bugs and the fine dust that blows across South East Queensland yards. Even if you have no trees, your neighbour's will kindly lend you theirs the moment the pool is uncovered.
Two habits do most of the work here:
- Run the net across the surface before anyone swims, and again after.
- Empty the skimmer basket at the same time. Debris the net misses gets drawn into that basket, and a clogged basket starves the pump and filter of flow. Pumps and filters are expensive to replace on an inground pool; keeping the basket clear is the cheapest insurance you'll ever buy.
A quick daily skim during heavy-use summer weeks stops the slow build-up that turns a five-minute job into an hour.
Brush the walls and floor without scratching the gelcoat
Use a soft-bristled or nylon pool brush on fibreglass — never a steel or stiff wire brush, which will scratch the gelcoat and leave permanent dull marks. This is the one place a fibreglass pool needs different handling to concrete. Concrete owners reach for aggressive brushes to scour a rough surface; on a smooth gelcoat that same brush does damage, and the fine scratches it leaves actually give algae the footing it otherwise lacks.
Fit the brush to a telescopic pole so you can reach the deep end, the steps and the swim-outs without getting in. Work around the whole shell once a week: the waterline first, where sunscreen and body oils leave a faint tide mark, then down the walls and across the floor. Brushing lifts the film and loose grime into the water where the filter can catch it, and knocks back any algae before it's visible.
Pay attention to the shaded corners and the steps. Water moves slowly there, the sun doesn't reach, and that's where a green haze starts if anywhere does.
Vacuum the floor once a week
Vacuum the pool floor weekly to remove the settled grit and organic matter that brushing stirs up. Brushing and vacuuming are a pair — brush first to lift everything off the surfaces, then vacuum to pull it out of the pool for good. Do them in the wrong order and you're vacuuming a floor you're about to make dirty again.
You have three broad options, and the right one depends on how much of the job you want to hand off:
| Method | Effort | Best for |
|---|---|---|
| Manual vacuum head on the telescopic pole | Highest — you push it by hand | A thorough clean and full control over trouble spots |
| Suction or pressure cleaner | Low — runs off your existing pump | Steady week-to-week maintenance |
| Robotic cleaner | Lowest — independent unit, scrubs and filters | Owners who'd rather not touch it at all |
Whichever you choose, empty its basket or bag afterwards. A full cleaner just pushes debris around. If you're weighing up a machine, our guide to choosing the right pool cleaner for your pool walks through which type suits a fibreglass shell.
Keep the water balanced so the cleaning holds
Balanced water is what stops a clean pool going cloudy or green between cleans, and it's the step most owners neglect. You can skim, brush and vacuum perfectly, but if the chemistry is off the water still turns. The two numbers that matter most:
| Reading | Target range | Why it matters |
|---|---|---|
| Total alkalinity | 80–120 ppm | Buffers the water and stabilises pH — set this first |
| pH | 7.2–7.6 | Keeps chlorine working and protects the gelcoat and fittings |
Set the alkalinity before you touch anything else, because it's what holds the pH steady. Then adjust pH into the 7.2 to 7.6 band. This order matters: a large share of pool owners don't realise their chlorine simply won't sanitise the water when pH drifts too low or too high — you can be adding chlorine and still growing algae. If your fill water is hard, a scale inhibitor helps keep mineral deposits off the shell and fittings.
Test at least weekly, more often in summer. SEQ storms dump phosphates and organic load into a pool fast, and a warm pool after heavy rain is exactly the condition algae wants. Catching the numbers early is a strip test and a cup of stabiliser; catching them late is a weekend. When a reading is badly out or the water's already turned, knowing when and how to shock your pool is what brings it back.
Can you keep a pool clean without chemicals?
You can cut your chemical use dramatically, but no pool stays safe to swim in with zero sanitiser — the water still needs something to kill bacteria and algae. What you can do is reduce how much you depend on it, and this is where a pool cover earns its keep. A cover is the single most useful tool for keeping a pool clean short of the cleaning itself.
A cover stops leaves, bugs, dust and pollen entering the water while the pool sits idle, which is most of the day. Less debris means less skimming, less vacuuming and less organic load for your sanitiser to burn through — so chlorine lasts longer and you add less of it. A cover also cuts evaporation and blocks UV, which otherwise destroys free chlorine through the middle of a Queensland day. Cover the pool faithfully each night; the amount of debris that blows in over a few uncovered hours is genuinely surprising.
Mineral and magnesium systems and saltwater chlorinators are the other route people mean by "chemical-free". They soften the sanitiser rather than remove it — the pool still runs on a controlled, gentler form of chlorine — but they make the water far kinder on skin and eyes and reduce the sting of handling raw chemicals.
A weekly rhythm that keeps it sparkling
The whole method comes down to being diligent rather than heroic. Clean the pool thoroughly at least once a week, and more often when it's getting heavy use through summer. A thorough clean is the four steps together: skim the surface, brush the walls and floor with a fibreglass-safe brush, vacuum up what you've loosened, and check the alkalinity and pH. Empty every basket you touch along the way.
Do that consistently and the hard work never builds up in the first place. For the full seasonal picture — filter runtimes, backwashing, winterising and the jobs that come round monthly rather than weekly — see our fibreglass pool maintenance guide, and browse the rest of our pool care tips for the smaller questions that come up along the way.
FAQs
What is the best way to clean a fibreglass pool?
A weekly routine of four steps: skim the surface, brush the walls and floor with a soft nylon or fibreglass-safe brush, vacuum the floor, then test and adjust the water so alkalinity sits at 80–120 ppm and pH at 7.2–7.6. Skim daily during heavy use and keep the pool covered when it's idle, and the water stays clear with minimal effort.
What brush should I use on a fibreglass pool?
Use a soft-bristled or nylon brush only. Steel and stiff wire brushes scratch the smooth gelcoat, leaving permanent dull marks and fine grooves that actually give algae somewhere to grip. Fit the brush to a telescopic pole so you can reach the deep end and steps without getting in.
Can I keep my pool clean without chemicals?
You can cut chemical use heavily but not eliminate it — every pool needs some sanitiser to kill bacteria and algae. A pool cover, a mineral or magnesium system, and diligent skimming reduce how much you need. A cover in particular keeps debris out and blocks the UV that burns off chlorine, so you add far less.
How often should I clean my pool?
Do a full clean at least once a week, and more often in summer or after heavy use. Skim the surface and empty the skimmer basket daily when the pool is in regular use, and test the water weekly — more often after SEQ storms, which dump phosphates and organic load that feed algae fast.
Why does my pool go green even when I add chlorine?
Almost always because the pH is out of range. When pH drifts too low or too high, chlorine can't sanitise properly, so you can be adding it and still growing algae. Set total alkalinity to 80–120 ppm first, then bring pH into 7.2–7.6, and the chlorine starts doing its job again.
