Scheduled visit
The pool turns green again days after treatment
The pool was treated and cleared, and within days the green tint is back. The water may have looked fine for a moment before the green returned, or it never fully cleared. Because the treatment was applied and the algae came straight back, the problem is usually not the chemicals — it is that the water is not being turned over or filtered well enough to keep them working.
Pool Maintenance
Normally scheduled. Equipment failures that would leave the pool stagnant are handled sooner.
Call nowBook a pool check on WhatsApp01LIKELY CAUSES
What usually sits behind this symptom, and what tells one cause from another.
Insufficient water turnover for the pool size
The pump runs too few hours, so the water is not being turned over enough to clear and stay clear.
A filter that is no longer doing its job
The filter is clogged, channelled or undersized, so fine algae passes straight back into the pool.
Poor circulation leaving dead spots
Areas with little flow stay still, and algae regrows there first.
Stabiliser or chemical balance out of range
High stabiliser or a balance issue is binding the sanitiser so it cannot work.
A recurring contamination source
Organic matter is entering the pool — dust, plants or bather load — faster than it is removed.
02BEFORE ANYONE VISITS
What you can safely check.
- Note how quickly the green returns and whether it starts in the same spots.
- Check how many hours the pump runs each day and whether it matches the heat.
- Look at the filter pressure and note whether it has been cleaned recently.
- Avoid repeatedly shocking the pool without addressing the circulation and filtration.
03WHAT WE MEASURE
We test the chemistry, but we look harder at the turnover, the filter and the circulation, because a pool that greens again days after treatment is usually failing on one of those. We check the run time against the pool size, read the filter pressure and its condition, and find the dead spots where the algae is regrowing first.
04IN A VILLA
A villa pool is used in bursts and sits in full sun, so the demand on the chlorine swings hard, and the pump hours that were fine in winter are not enough in summer. When the water is not turned over enough, the same treatment that cleared the pool cannot keep it clear, and the green returns within days.
05THE FIX
Which repair, and when.
A pool that keeps greening is not being fixed by more shock — it is telling you the system is not keeping up. Repeatedly shocking without fixing the turnover or filtration wears the water, costs more in chemicals, and leaves the pool unusable for days at a time.
Raise the run time and improve circulation
The water is not being turned over enough for the heat and use.
Clean or service the filter
The filter is clogged, channelled or past its service point.
Correct the chemistry and stabiliser level
The balance is binding the sanitiser so it cannot hold.
06WHAT DECIDES THE FIX
The same symptom can lead to different repairs. These are the things that decide which way it goes.
- How quickly the green returns, which points at turnover rather than a one-off.
- Whether it starts in the same dead spots, which points at circulation.
- The pump run time against the heat and the pool size.
- The filter pressure and its condition, which drives how well it clears the water.
- The stabiliser and balance, which can bind the sanitiser.
07HOW A VISIT GOES
What to expect when we come out, and why the order matters.
Test the water
The chemistry and stabiliser are measured to see what is binding the sanitiser.
Check the turnover
The run time is measured against the pool size and the season.
Check the filter
The pressure and the media are inspected to see whether it is clearing the water.
Find the dead spots
Circulation is checked where the green returns first.
Correct the system
Run time, filter, circulation and balance are corrected so the clear holds.
08KEEPING IT FROM RETURNING
Once it is fixed, these steps make the fault less likely to come back.
- Raise the pump hours as the heat rises, before the pool starts to turn.
- Clean or backwash the filter on schedule, not only when the pressure climbs.
- Watch where the green returns first, because that is the dead spot to fix.
- Keep the balance and stabiliser in range so the sanitiser can do its job.
- Clear organic matter — dust, leaves, heavy bather loads — before it feeds the algae.
09Typical villa pool servicing
Quoted per visit or on a regular schedule
Depends on pool volume, equipment set and visit frequency. Equipment repairs are separate and quoted after inspection. We do not carry out pool construction or full renovation.
10QUESTIONS
- Why does it go green again so fast?
- Because the water is not being turned over or filtered well enough for the chemicals to keep working. The treatment cleared the algae, but the system could not keep it clear.
- Do I need more chemicals?
- Usually the chemicals are not the problem. A pool that keeps greening needs its turnover, filter or circulation corrected, otherwise more chemical just keeps being wasted.
- How many hours should the pump run?
- Enough to turn the water over, which depends on the pump and the pool size and rises with the heat and use. Too few hours is a common reason a cleared pool greens again.
- Why does it start in the same spots?
- Those are the dead spots where the water does not circulate. Algae regrows there first because the sanitiser never really reaches them.
- Is the filter the problem?
- It can be. A clogged, channelled or undersized filter lets fine algae straight back into the pool, and the water greens again even after a proper treatment.
- What does the filter pressure tell me?
- A steady climb means the filter is loading and needs cleaning. If it has not been cleaned recently, that is often part of why the green keeps returning.
- Can high stabiliser cause it?
- Yes. When stabiliser is too high it binds the chlorine so it cannot sanitise, and the pool behaves as if it is under-dosed even when the reading looks fine.
- Should I shock it again?
- Shocking clears the algae that is there, but if the turnover and filtration are not corrected the green returns. The system needs fixing, not just re-shocking.
- Why is summer so much worse?
- Because heat and sun grow algae faster and burn off chlorine quicker, and the pool is used more, so the demand rises while the same pump hours become insufficient.
- How do I make the clear last?
- Match the run time to the season, keep the filter clean, fix the dead spots, and keep the balance and stabiliser in range — then the treatment holds.