Why Pools Turn Green So Fast in Bali
Bali's warm temperatures, high humidity, and frequent rain make it the perfect breeding ground for algae. Even well-maintained pools can turn green overnight, or at least it seems that way, if the weather takes a turn for the worse.
But what really takes owners by surprise is just how quickly algae takes off here compared to other places. The sun in Bali is super-hot, which accelerates the evaporation of chemicals. When it rains, chlorine levels get diluted, and the filtration system goes haywire. Add all this to the mix of dust, insects, and leaves from the surrounding gardens, and you have a recipe for disaster if you're not keeping up with your maintenance.
The good news? A green pool is totally fixable. And with the right habits in place, it's very preventable too.
1. First Things First: Stop Swimming For Now
It can be tempting to think that a slightly green pool is still safe to use, but trust us - it's not. Not only is it dirty, but it's also a sign that the chemical balance has been thrown off, allowing algae and bacteria to thrive. Not to mention that certain water irritants can affect your skin, eyes, and respiratory system.
So what to do? Stop swimming until:
- The chlorine levels are back up.
- The algae is fully killed.
- The water is nice and clear.
It's always better to err on the side of caution, especially if you have guests coming to stay.
2. Get Your Water Tested (Or Ask a Professional to Do It For You)
Before you can tackle fixing a green pool, you need to know what's going on with the water balance. That means testing for things like:
- Chlorine levels (which are often way too low).
- pH levels (which can be way too high, making chlorine pretty much useless).
- Alkalinity (which controls the pH levels).
- Phosphates (which are basically algae's favorite food).
Don't skip this step; without proper testing, you're basically flying blind. And that's a surefire way to end up wasting time and money on the wrong chemicals.
If you don't have testing gear yourself, don't worry. Any decent pool service can handle it for you.
3. Shock the Pool With a Super-Strong Chlorine Dose
"Shocking" the pool means adding a much stronger dose of chlorine than usual. This "super-chlorination" will kill the algae in no time and get your pool chemistry back on track.
In Bali's tropical climate, algae love to thrive because:
- The water is always so warm.
- The sun is super-strong, making UV exposure intense.
- When it rains, chlorine levels get diluted and the filtration system gets overwhelmed.
So, yes, pools in Bali often need a much stronger shock treatment than you might use back home.
After shocking, be prepared for:
- At least 24 to 48 hours of no swimming.
- The water might turn cloudy before it clears.
- The pump will need to run continuously.
This step is crucial. Without proper shocking, the algae will come back, and probably faster than ever before.
4. Give the Pool a Good Brush-Down
Algae loves to cling to rough surfaces, so just cleaning the water won't do the trick. You need to get right down and brush the entire pool, including:
- All the walls.
- The steps and ledges.
- The floor surfaces.
- Corners (these are basically algae-hotspots).
- The tile lines.
- Around inlets and lights.
Many pool issues stem from poor brushing habits. Even high-end villas can struggle with algae if the walls aren't properly scrubbed. Proper brushing helps the shock treatment work more effectively and prevents algae from coming back.
5. Run the Filtration System Around the Clock Until the Water Clears
The filtration system is what removes dead algae from the water. Without a good filtration system, algae will remain suspended in the pool, keeping it cloudy or green.
In Bali, techs often run the pump:
- 24 to 48 hours continuous.
- Longer if the pool was particularly green.
Think of filtration as the final step of algae removal. Once the chemicals kill it, the filter takes out the dead algae from the water. If the pump is weak or runs for too short a period each day, the pool may struggle to recover.
6. Vacuum the Pool to Get Rid of Dead Algae
After brushing and shocking, the algae will fall to the bottom of the pool as fine dust.
If you don't vacuum this out, it will just circulate back up and give the water a cloudy appearance.
Vacuuming ensures:
- The pool bottom is properly cleaned.
- Dead algae doesn't get reattached to surfaces.
- The water clears up faster.
- Filtration isn't overwhelmed.
A properly vacuumed pool will often go from green back to blue much faster.
7. Balance the Pool Chemistry Correctly
This is the final step, and it's super important. You need to get the chemistry of your pool back on track, which means balancing the levels of:
- Chlorine.
- pH.
- Alkalinity.
- Phosphates.
Get this wrong, and you'll be back where you started. But get it right, and you'll be swimming in crystal-clear water in no time. Once the algae are finally defeated and hauled out of the pool, it’s essential to rebalance the water.
A lot of people forget about this step, but let me tell you, getting the chemistry right is crucial to prevent the water from turning green all over again.
Your technician should check and adjust:
- Chlorine levels to make sure they're just right.
- pH levels.
- Alkalinity.
- Stabiliser (to prevent chlorine loss).
- Algaecide if that's still needed.
Water that's got the right balance will last longer, uses less chemicals, and stays sparkling clear even when the sun is beating down or it's raining cats and dogs.
8. Clean the Filters and Get Those Baskets In Working Order
A green pool puts a heck of a lot of strain on your filtration system.
All the dead algae ends up clogging the filters, and if you don't get them cleaned out, the system starts to struggle, and the water stays cloudy for days on end.
Your technician needs to give the following areas a good clean:
- The skimmer baskets to make sure they're free flowing.
- The pump basket.
- the Cartridge or sand filter, all of it needs to be spotless.
A clean filtration system is the backbone of a healthy pool; it's essential.
9. Get To The Root Of Why Your Pool Turned Green In The First Place
Fixing the pool is one thing, but preventing it from going green again is even better news. Pools in Bali turn green for a few pretty predictable reasons.
Some of the most common root causes include:
- A big downpour that weakened the chlorine levels.
- Low chlorine levels or neglected chemical top-ups.
- The pump not running often enough.
- Bad brushing habits, you need to get in there and give it a good scrub.
- Debris falling into the pool, leaves, flowers and frangipanis.
- High phosphate levels from organic matter.
- Old or weak filtration equipment that's just not doing the job.
Once you identify the root cause, you can refine your maintenance routine and reduce the risk of future algae blooms.
10. Keeping Your Pool From Turning Green Again, Long-Term Prevention
The long game here is about consistency. In Bali, chucking some chlorine in the pool isn't enough on its own. You need to get the whole routine right to keep it blue and healthy.
Weekly prevention habits:
These little steps make all the difference:
- Test the chlorine and pH.
- Give the walls, floors and steps a good brush.
- Skim off any leaves or dirt.
- Vacuum the pool.
- Get the skimmer basket clean.
- Top up the chlorine and stabiliser as needed.
- Keep a close eye on the water clarity.
During the rainy season:
Pools are at their most vulnerable when it's pouring with rain.
- Increase the pump runtime to keep the water circulating.
- Do a light shock treatment after any big storms.
- Keep an eye out for green patches in the corners.
- Make sure the drainage around the pool is clear.
Monthly maintenance:
Regular maintenance is key to keeping your pool stable over the long term.
- Give the filter a really good deep clean.
- Check the pump pressure.
- Clean the tile grout.
- Remove calcium buildup around the waterline.
Consistency is key here, a pool that gets brushed once a week hardly ever turns green.
Summary: What to do when your pool turns green?
✔ Stop swimming
✔ Check the water
✔ Slap a high dose of chlorine in there and shock the pool
✔ Give the pool walls, steps, and floors a good brush
✔ Run the filtration system until the water is spotless
✔ Vacuum the pool
✔ Get the chemistry right
✔ Clean the filters and baskets
✔ Take preventative measures
Conclusion: A Green Pool Is Easy To Fix And Even Easier To Prevent
A green pool can look a bit alarming, but with the right steps, it's a pretty straightforward problem to solve. The key is to act fast, get the chemistry right, brush thoroughly, and give the filtration system a bit of love.
Prevention is a lot easier than a cure.
With regular brushing, proper chemical levels, and a consistent maintenance routine, your pool can stay a beautiful, inviting blue all year round - even in the rainy season.
Need Help Keeping Your Villa Clean and Guest-Ready?
If you also need:
- Housekeeping
- Deep cleaning
- Move-in/move-out cleaning
- Mold & humidity control
- Villa inspections and reporting
We're here to help.
👉 Get in touch with us via WhatsApp or visit balicleaners.com to book your cleaning today
