When to change hotel pool water: yearly emptying, refilling and winter closing

Turkish pool rules require every public pool to be emptied and fully cleaned at least once a year, and children's pools once a month. Hotels usually schedule the annual empty for the quietest week, check the shell and groundwater first, confirm with the local water authority where the water may go, then refill and balance before reopening.

The pool has run since May, the tile at the waterline has gone dull, and the regulation says it must be emptied and fully cleaned at least once a year. The week you choose, and what you check before the first liter leaves the pool, decide whether this is a maintenance job or a repair bill. This guide turns the rule into a plan: the volume arithmetic, the choice of week, a drawdown that protects the shell, the cleaning and inspection list, the refill and the first balance, and the winter question of keeping the pool full or empty.

What does Turkish pool regulation require for emptying and cleaning?#

Every pool open to the public must be emptied and fully cleaned at least once a year, and children's pools must be emptied and cleaned once a month. The rule sits in the Regulation on the Health Principles for Swimming Pools, published in the Resmî Gazete on 6 March 2011 (No. 27866) and amended on 15 December 2011 (No. 28143), according to the consolidated text on the Presidency's legislation database. It covers open and closed pools used for swimming, cooling off, fun or sport and open to the public. Health-purpose spa and mineral water pools, and pools not used commercially, are outside it.

The wording is a floor, not a schedule. At least once a year is the minimum the text sets; a pool with heavy bather load may need more, and your provincial health directorate is the body to confirm that with. Children's pools are defined by the same text: at most 50 cm deep, separate from the adult pool, with their own water treatment, emptied and cleaned monthly.

In practice, "emptied and fully cleaned" means the water leaves, the shell is cleaned and inspected, and the pool is refilled. A partial drain and a top-up is not that, and an inspector reading the record book will see the difference. The provincial health directorate inspects the pool, the water and the chemicals every month, including the analysis record books, and the operator keeps laboratory reports for one year to show inspectors. A pool that meets the rules over a calendar year receives a Clean Pool Certificate (Temiz Havuz Sertifikası), which is a reason to keep the annual clean documented rather than remembered.

The annual empty is when you can inspect and repair what water hides: the shell, the joints, the drain covers and the balance tank. The same regulation drives many other duties around water, staff and records, covered in the pool health regulation as a checklist for water, staff and records.

How do you calculate a hotel pool's volume?#

Measure in meters and multiply: length × width × average depth gives cubic meters, and one cubic meter is 1,000 liters. A rectangular pool with one depth is one multiplication. A pool that slopes from shallow to deep uses the average of the two ends: for example, 1.2 m at the steps and 2.0 m at the deep end average 1.6 m.

Split anything that is not a rectangle into rectangles and add them; an L-shape is two boxes, and a circular pool is π × radius² × depth. Subtract what displaces water: wide steps, a beach entry, a raised floor, an integrated spa or a swim-out bench. A 10 percent error on a large pool is a lot of cubic meters.

Check the figure against the as-built drawings and against the water meter on the next fill. If the two disagree, the meter is usually right. The number earns its keep three times: refill time is volume divided by supply rate, the discharge plan needs the volume leaving the site, and the water bill is volume times the local tariff.

Write the figure on the plant room wall and in the pool log so every shift and every contractor uses the same one, and recalculate after any renovation. Dosing depends on the same number, but the doses themselves come from the test kit and the water operator's training, not from a rule of thumb passed between hotels.

Which week should you empty the pool?#

The quietest week of the season, in mild weather, with the water supply measured and the staff and contractors booked: not a full week, and not a heatwave. Read your own occupancy curve rather than the calendar. The shoulder weeks either side of the peak usually cost least in turned-away rooms, and the loss is measurable before you commit.

Weather decides the experience. A heatwave turns an empty pool into a complaint, while heavy rain and frost slow the work and the refill. Confirm the water supply first: measure the flow rate and pressure at the hotel's own meter, because a refill that takes days instead of hours changes the whole plan. Check the inspection calendar too. The provincial health directorate inspects monthly, and a pool in the middle of a refill cannot be sampled properly.

Book the people, not just the week: the tiler, the pump technician and the trained pool water operator all need the same dates. Tell guests before they book: put the closure dates in the booking confirmation for those dates, and name the alternative, whether that is a second pool, the sea or a partner property. Do not empty a pool in peak season to fix something cosmetic. A stain or a dull tile line can wait for the planned week; a leaking shell cannot.

How do you empty a pool without damaging it?#

Slowly, with the shell and the groundwater watched, and only after your local water and sewerage authority has told you where the water may go. Groundwater is the first question, not the last. An empty shell weighs far less than the ground pressing on it, and in high groundwater a pool can lift or crack. Ask an engineer, keep a minimum water level if the design calls for it, and find out whether the pool has hydrostatic relief.

Draw the water down in a controlled way: pump or gravity to the balance tank and out, isolate the treatment plant, never run a pump dry, and watch the shell as the level falls. Stop if cracks, movement or unusual seepage appear.

Where the water goes is a local question. No national text was found that states where drained pool water may be discharged, so the answer comes from your water and sewerage authority (İSKİ, ASKİ and their equivalents elsewhere) and your discharge permit. Ask before you start, and keep the answer in writing. Agree the rate as well as the route: a large volume released quickly can surcharge the sewer or flood a neighboring plot, and the authority cares about both. Let the chlorine decay or dechlorinate before discharge as good practice, and follow whatever your authority requires on top of that.

Record the event: start and end meter readings, photographs of the shell at each stage, and the authority's written answer filed with the pool records. Keep the site safe while it is empty: fence the pool, keep depth markings visible, and never let one person work alone in an empty shell.

What should you clean and check while the pool is empty?#

Everything you cannot see or reach when it is full: the shell, the waterline, the joints, the inlets, the balance tank and the plant room. Clean the tile line, remove scale, and look for cracks. A structural crack is an engineer's call; a hairline in grout is maintenance. Re-grout, replace loose tiles, check expansion joints, ladder anchors, handrails, depth markings and the pool rules board.

On the hydraulics side, clear skimmers, main drains, equalizer lines and return inlets, and confirm every drain cover is fixed and undamaged, because a missing or loose cover is a serious safety fault. Empty and clean the balance tank, and inspect the float valves and level controls that keep the pool from overflowing or running dry.

In the plant room, check strainer baskets, pump seals, dosing lines and probes, the filter pressure gauge and the backwash sight glass. Probes that read wrong all summer should be calibrated or replaced now. Check the safety equipment too: lifeguard equipment, ring buoys, the rules board and the display board that shows the latest temperature, pH, free chlorine and microbiological results. Photograph each item before it is covered again. Next year's comparison starts from these photographs.

How do you refill and balance the water before reopening?#

Refill at a rate the shell and the supply can take, then balance in order: total alkalinity first, then pH, then disinfectant, then stabilizer, and record the first full set of results. Match the refill rate to the supply and to the engineer's advice. A fast fill on a dry shell stresses finishes, and filling in stages costs nothing but time.

Meter the water. The annual fill is the largest single water event of the year, and the meter reading is both a cost line and a leak check for the weeks that follow. Balance in order, because each step depends on the one before it: total alkalinity gives pH its stability, pH decides how well the disinfectant works, then the disinfectant, then cyanuric acid. The doses come from the test kit and the water operator's training.

Circulate and filter before you test again. A freshly filled pool reads differently from one that has run for a day, and the first reading is not the one to file as normal. Record the first full set: temperature, pH and free chlorine from the operator's tests, plus the daily colour, turbidity and cyanuric acid and the weekly total alkalinity, and post the latest figures where users can see them. The daily routine that follows is covered in measuring and correcting pH and chlorine each day.

Reopening checks: plant running normally, safety equipment in place, signage and fencing correct, and the log signed by the responsible manager. Remember the consequence of a failed sample: a microbiological failure closes the pool until a new sample passes, and a chemical failure brings a written warning first. Finding the problem during the refill is cheaper than finding it in July.

Should a seasonal hotel empty the pool for winter or keep it full?#

Both work; the choice turns on the shell, the groundwater, the local discharge rules and how the pool will be covered, and the annual clean can be timed to spring start-up either way. Keeping it full keeps the shell loaded, which suits sites with high groundwater. The winter work becomes a cover, reduced circulation, chemistry checks at a lower frequency, and a thorough clean at spring start-up.

Emptying it is only for pools whose shell and groundwater allow it. The pool then needs protection from rain, debris and animals, and the shell needs to be looked at during the winter rather than assumed. The regulation does not force an autumn empty: "at least once a year" can be satisfied at spring start-up, so the winter decision is operational, not legal.

Cover safety matters either way: a cover is a safety device only if it is rated for that use. An unsecured cover on a full pool is a hazard, not a protection. Freeze risk sits mostly in the pipes and the plant, not in the pool: standing water in lines and exposed pipework is the part to drain, following the plant's design. Spring start-up has its own sequence and its own four-week window, and the annual clean slots into it naturally if you did not empty in autumn. The surrounding work is covered in closing a seasonal hotel for winter and reopening a seasonal hotel in the last four weeks.

What to do next#

Put the annual empty on next year's calendar now, with four things attached to the date: the pool's volume in cubic meters, the week chosen from your own occupancy curve, the discharge route confirmed in writing by your local water and sewerage authority, and the first balance record filed after reopening. The pieces fit as one loop: the regulation sets the minimum, the volume sets the arithmetic, the week protects the season, the drawdown protects the shell, and the refill and first balance protect the reopening.