You’re watching the water level in your pool drop and you can’t work out why. Every few days it’s lower. You’re topping it up, the bill is climbing, and if you’re managing the villa from overseas, there’s a nagging worry that something expensive is going wrong that nobody’s telling you about.

Here’s the honest answer up front: in Bali, a dropping pool is often just evaporation — but sometimes it’s a leak, and the two need completely different responses. Evaporation is normal and free to ignore. A leak wastes water and chemicals every single day, quietly undermines your pool structure, and only gets more expensive the longer it runs.

The good news is you can tell them apart in 24 hours with a bucket and no tools. This guide shows you how, explains where Bali pools actually leak, and tells you when it’s time to bring in leak detection and a pressure test.

First: Bali pools lose a lot of water to evaporation

Before you assume the worst, know that a Bali pool loses more water to plain evaporation than a pool in a cooler climate — sometimes noticeably so. Three things drive it:

  • Heat. Warm air and warm water evaporate fast, all year round.
  • Sun. Long hours of strong tropical sun pull water off the surface every afternoon.
  • Wind. An exposed pool — rooftop, clifftop in Uluwatu, or open garden in Canggu — loses more to breeze than a sheltered courtyard pool.

On a hot, breezy week it’s normal for a Bali pool to drop a couple of centimetres. Add splash-out from a busy rental, backwashing the filter, and the odd overflow, and the level moves around more than owners expect. So a falling level on its own is not proof of a leak. What you need is a way to separate normal loss from a real problem — which is exactly what the bucket test does.

The bucket test: leak or evaporation, settled in 24 hours

This is the standard way pool technicians rule a leak in or out, and you (or your villa staff) can do it in five minutes:

  1. Fill a bucket with pool water and set it on the first or second step, so the bucket water and the pool water start at the same level. If your pool has an auto-fill, switch it off for the test.
  2. Mark the water line inside the bucket and the pool water line outside the bucket (tape or a marker).
  3. Leave it 24 hours. Don’t run the pool differently and, ideally, don’t swim.
  4. Compare the two drops.

Read it like this:

  • Both dropped the same amount → it’s evaporation. No leak. You can relax.
  • The pool dropped noticeably more than the bucket → you have a leak. Time to investigate.

For a sharper result, run the test twice — once with the pump running and once with it off. If the pool loses more water with the pump on, the leak is likely on the pressure side of the plumbing. If it loses water at the same rate either way, the leak is more likely in the shell or a fitting. That single clue saves a lot of diagnostic time.

Where Bali pools actually leak

If the bucket test points to a leak, it’s almost always one of these — and a few are specific to how and where pools get built here:

  • Plumbing lines. Cracked or poorly glued pipe joints on the suction or return lines. Common where a pool was built fast or cheaply, and a frequent culprit in older villas.
  • Skimmer and fittings. The seal where the skimmer, return jets or lights meet the pool shell is a classic leak point as it ages or shifts.
  • Structural cracks in the shell. Concrete pools can crack from ground settlement and movement — a real factor in Bali — or from earth tremors. Even a hairline crack leaks continuously.
  • Around underwater lights. The conduit and housing behind a pool light is a surprisingly common slow-leak source.
  • Tile and grout / waterline. Failed grout at the waterline or behind tiles lets water track out slowly.

Bali adds two things a Western pool guide won’t mention: a share of villa pools were built to tight budgets with variable workmanship, and the ground genuinely moves here. Both mean leaks are more common than owners assume — and more likely to be structural.

Signs it’s a leak, not evaporation

Beyond the bucket test, these point to a real leak:

  • You’re topping up more than about 3–5 cm a week and the weather doesn’t explain it.
  • Wet or soggy ground, or unusually green grass near one side of the pool or along the equipment lines.
  • Cracks in the pool deck or movement in the coping.
  • Air bubbles from the return jets when the pump runs (air being drawn in through a suction-side leak).
  • You can’t keep chemistry stable — chlorine and balance keep drifting because you’re constantly diluting with fresh top-up water. (A leak is a common hidden reason a pool keeps going green.)
  • The pump loses prime or runs noisy/dry.

Why a leak is worth fixing now, not later

A slow leak feels ignorable — you just top it up. But it’s costing you every day it runs:

  • Wasted water and chemicals. Every litre that leaks out takes your chlorine and balancing chemicals with it, and you pay to replace both.
  • Structural damage. Water escaping behind the shell erodes the ground supporting your pool and can worsen the very crack that’s leaking — turning a small repair into a major one.
  • Equipment strain. A suction-side leak makes the pump draw air, which shortens its life.
  • Foundation and landscaping damage. Constant leakage into the surrounding ground can affect decking, retaining walls and nearby structures — a serious issue on Bali’s sloped, clifftop sites.

For a remote owner, the real risk is that a leak runs for months undetected because no one is standing at the pool doing the maths. That’s the expensive scenario — and the reason it’s worth diagnosing properly the moment the bucket test flags it.

How professional leak detection and pressure testing works

Finding a leak isn’t guesswork. Here’s how we run it, built to be transparent for owners watching from overseas:

  1. On-site survey within 24 hours. We confirm the leak, check the obvious fittings, skimmer and visible structure, and note the pump-on vs pump-off behaviour.
  2. Pressure testing the plumbing. We isolate and pressurise the suction and return lines to find whether — and where — the underground pipework is leaking, without digging blindly.
  3. Locating the source. Combining the pressure test with dye testing at fittings and cracks, we pinpoint the leak rather than tearing up your deck on a hunch.
  4. A clear written quote before any repair — you approve the cost first.
  5. The repair: re-sealing fittings, repairing or re-running plumbing, patching structural cracks, or resetting a light housing, depending on the source.
  6. A written report to your WhatsApp: what was leaking, what we did, and confirmation the pool now holds its level.

This is exactly what our Repair & Equipment service is built for — plumbing repair and pressure testing are core to it, precisely because leaks are so common and so easy to misdiagnose.

Can you fix a pool leak yourself?

Some of it, sometimes. A visibly cracked skimmer seal or a loose fitting can be re-sealed by a competent handyman. Waterline grout can be redone.

But the moment the leak is underground plumbing or a structural crack, DIY stops. You can’t pressure-test buried lines without the right kit, and guessing means digging up the wrong section of deck. For anything past a visible surface fitting — and for any owner who isn’t on-site to supervise — a proper detection job is faster and cheaper than trial and error.

How to avoid slow leaks going unnoticed

The danger of a leak isn’t the leak — it’s how long it runs before anyone notices. That’s a monitoring problem, and it’s solved the same way most Bali pool problems are:

  • Someone checks the water level and top-up rate regularly, so a leak is caught in weeks, not months.
  • A record of top-ups and chemistry makes a slow leak obvious early — a sudden jump in how often the pool needs filling is the giveaway.
  • Catch structural movement early — small deck cracks and shifted coping get noted before they become shell leaks.

If you own the villa remotely or rent it out, this is the case for a maintenance contract with reporting: our pool maintenance includes a written report after every visit, so a rising top-up rate gets flagged to you long before it drains your pool — or your budget. We cover Bali’s main villa areas including Canggu, Seminyak, Ubud, Uluwatu and Sanur.

Losing water and not sure why? Get it diagnosed

Do the bucket test first — it costs nothing and tells you whether you even have a problem. If the pool loses more than the bucket, don’t let it run.

Message us on WhatsApp for leak detection & a pressure test → We survey within 24 hours, pressure-test the plumbing, send a clear quote before any repair, and confirm in writing once your pool holds its level again.

Frequently asked questions

How much water loss is normal for a pool in Bali? On a hot, sunny, breezy week it’s normal to lose a couple of centimetres to evaporation — more for an exposed clifftop or rooftop pool. If you’re topping up more than roughly 3–5 cm a week and the weather doesn’t explain it, run the bucket test to check for a leak.

How do I know if my pool is leaking or just evaporating? Do the bucket test: float or step a bucket of pool water so it matches the pool level, mark both lines, and wait 24 hours. If the pool drops more than the bucket, you have a leak. If they drop by the same amount, it’s evaporation.

Where do Bali pools usually leak? Most often the underground plumbing (cracked or poorly glued joints), the skimmer and fitting seals, structural cracks in the shell from ground movement or tremors, and around underwater lights. Budget construction and Bali’s moving ground make plumbing and structural leaks more common here than in many climates.

Is a small pool leak really worth fixing? Yes. A slow leak wastes water and chemicals daily, keeps your chemistry unstable, and — worse — erodes the ground supporting the pool and can enlarge the crack that’s leaking. Fixing it early is far cheaper than repairing the structural damage a long-running leak causes.

Can a leak make my pool turn green? It can contribute. Constant top-ups with fresh water dilute your chlorine and balancing chemicals, so a leaking pool is much harder to keep sanitised and clear — which is one hidden reason a pool keeps going green despite regular dosing.