How a pool is closed for the winter will affect how easy it will be to open in the spring. The ultimate objectives in closing a pool for the winter months are to preserve water quality, protect equipment and surfaces, and have the pool ready to enjoy with minimum effort requried when opened. Proper closing helps to avoid costly issues such as freeze-thaw damage to pool surfaces, damaged or broken pool equipment, and underground pipe damage. Improperly closed pools can lead to a costly and frustrating opening process. Whether a pool is completely closed or just put on reduced maintenance, it is important to be sure that the pool is not neglected over the course of the winter.

1. Take care of any unresolved issues. Any water-quality problems should be addressed before the pool is closed. Water problems that are not solved before closing will still exist upon spring opening. In fact, many of these problems can become worse over the course of the winter, which could make spring opening a real challenge. For example, a chlorine demand that is not satisfied before closing can continue to grow during the winter, especially in warmer areas.
2. Balance the water. Scaling or corrosive conditions can persist and cause problems to pool surfaces and equipment, even with the circulation system off. Water has a natural tendency to seek its own balance (and that could mean taking elements from its surroundings) and this does not stop during the winter months. Properly balanced water will provide better protection for pool equipment and surfaces during the off-season, as well as during peak season.
3. Prevent algae. To help prevent algae growth over the winter months, a winter algaecide may be used. Be sure that the pool has been circulated adequately before shutting down so that the algaecide is properly dispersed. In warmer climates, a mid-winter application may be necessary.
4. Prevent stains. A sequestering agent (metal/scale treatment) applied to the water will help prevent any dissolved metals from staining the pool surface. Metals that may become insoluble during the off season are not being filtered as they would be in season. Sequestering agents will help hold the metals in solution and prevent staining. If a pool stains during the winter, it can be several months before it is treated. This would make the stain much more difficult to treat as fresh stains are always easier to remove. Sequestering agents can also help prevent the formation of scale, particularly in hard-water areas. Scale buildup on pool surfaces or equipment can lead to costly repairs.
5. Clean, clean, clean! Remove any dirt and debris from the water. Leaves, dirt and other unwanted debris can cause unsightly staining if left on pool surfaces for long periods of time. These stains will be more difficult to remove months later.
6. Shut down equipment. Be sure to turn off the equipment, including timers. Pumps can be damaged by running without proper water flow, so it is important to be sure that the timers are disabled so that the pump does not inadvertently start. Be sure to turn off lights as well; because the light lenses will become hot with the bulbs on, contact with cold water can cause them to crack. Remove and store any equipment that may be damaged due to extreme weather conditions.
7. Lower the water level and drain the lines and equipment. Remove enough water from the pool so that the water level is at least below the skimmer. Water expands as it freezes, so be sure that water is removed from the lines or that antifreeze is added. Use non-toxic antifreeze that is appropriate for pools. Do not use automotive antifreeze. A shop-vac may be used to blow the water from the lines, and then the lines can be plugged to ensure that pipes do not crack over the winter. Alternatively, the water may be drained below the lines in order to ensure that all water is removed from the plumbing. It is inadvisable to completely drain in-ground pools due to hydrostatic pressure from groundwater in some areas. This can cause pools to crack or even pop out of the ground. Vinyl lined pools will wrinkle if completely drained and can be very time consuming and costly to repair. Pumps and other equipment should be completely drained by removing the drain plugs. All water should be removed from the filter to prevent damage to the filter housing. Be certain that there are no open valves that can leak water into the filter.
8. Close access to the pool. Swimming pools are a source of fun recreation and healthy activity, but they can be a safety issue if not secured properly. This includes the winter months when the pool is not being used. Children may be curious about a closed poo,l and pools are less likely to be supervised over the winter, so it is important to be sure that children do not have access. When public or commercial pools are closed, they should be secured against public access altogether. A partially drained pool could constitute a significant fall hazard.
9. Cover the pool. Covering the pool can help to limit the amount of leaves, dirt and other debris that enter the pool over the course of the winter. Solid covers that fit securely will help minimize unwanted debris, rainwater or runoff from entering the pool. If a solid cover is used, some type of siphon should be employed to remove water and other debris that may accumulate on the cover throughout the winter. Keeping the water covered will make spring opening much easier as there will be less debris removal and less potential for issues such as algae and chlorine demand. Mesh safety covers will let rainwater through, but provide a convenient method to keep leaves and other debris from entering the pool.
10. Store chemicals properly. Pool products should be stored in a cool, dry, well-ventilated area separate from other products such as fertilizers, motor oil, grease, paint and other household and garden chemicals. Mixing these common items with certain pool products can lead to unwanted and potentially dangerous chemical reactions. Keep pool-care products tightly sealed in the original container to prevent contamination. Always store pool products where they are inaccessible to children and pets. It is best to discard test kit reagents and/or test strips at the end of the pool season. Testing materials have a shelf life, which declines rapidly once opened. Because accurate testing is so important to proper pool maintenance, it is best to start with new test reagents and/or test strips at the beginning of the next season.

The pool owner or operator should continue to check on the pool over the course of the winter. Rain or snow can raise the water level or cause the cover to sink. If this happens, then take action immediately to correct the situation. Check for any heavy debris that may have fallen into the pool or on the cover and remove it right away. Proper off-season care will lead to a much easier spring opening and a more enjoyable pool season.

Click here to read more from The Association of Pool & Spa Professionals who provided this great article!

Here are a few key steps to follow when trying to keep your family swimming in clean and clear water all season long.

• When preparing to open your pool for the season, clean all leaves and other debris off the cover before removing it.
• Empty your skimmer baskets frequently. You’ll help minimize the amount of leaves that end up on the bottom of your pool.
• When cleaning the surface of your pool with a leaf net, work your way around the sides first, then clean from the middle of the pool to the sides.
• Empty your leaf net occasionally when cleaning your pool’s surface. Otherwise, the net’s contents may accidentally end up back in the pool.
• Keep the trees and shrubs around your pool trimmed back to minimize the amount of leaves and debris that end up in the pool.
• When opening your pool at the beginning of the season, run your filter around the clock until the water is completely clear.
• If your pool water appears green or has an unpleasant odor, the problem is probably caused by algae. Test for proper chlorine/sanitizer levels, and consult a pool professional if the problem persists.
• Keep your filter, pump, lint trap and skimmer baskets clean and in proper working condition to help ensure that your pool water stays sparkling clear.
• Pool inlets should be adjusted so the surface water is moving in a circular direction.
• Make a habit of checking and emptying skimmer and pump baskets regularly.

For other pool care tips like these visit PoolFYI.com by Pentair Water Pool & Spa.

You need to backwash when your pump pressure is 10-20 psi above the normal pressure rate for your pool, as well as after vacuuming.

To backwash:

• Turn off the pool pump
• Turn filter handle to “BACKWASH”
• Turn on the pool pump
• Run 2-3 minutes or until water runs clear
• Turn off the pool pump
• Turn filter handle to “RINSE”
• Turn on the pool pump
• Run for 10 seconds or until water runs clear
• Turn off the pool pump
• Turn filter handle to “FILTER”
• Turn on the pool pump
• Note lower pressure and resume normal use of pool

Remember, don’t backwash too often or your filter won’t reach its cleaning potential!

Regular backwashing will remove some, but not all, debris, so it is recommended to deep clean the filter at least 2-3 times per season. Follow the directions below to deep clean your pool filter.

Cartridge and DE filter:

1. Remove filter element(s) and rinse with water to wash away loose dirt
2. Soak element(s) overnight in a cartridge cleaner
3. Rinse element(s) thoroughly with clean water and replace

Sand filter:

1. Pour recommended amount of filter cleaner into pump strainer basket
2. Turn pump on and backwash into the filter
3. When water appears in sight glass, turn pump off and close all valves leading to and from filter, isolating the cleaner in the filter overnight
4. Next day, reopen valves and backwash until water is clear and no foam is visible
5. Run the rinse cycle and then return filter to normal operation

Phosphate enters your pool water from a variety of sources, including dust, rain, runoff from lawns and gardens, fill water, some pool chemicals, and leaves.  Why is it dangerous for your pool – particularly when it is hot?  Algae needs warmth, nutrients like phosphate, and sunlight to rapidly multiply and become a threat to pool sanitization through the rapid destruction of chlorine.

Pool owners can avoid high levels of phosphate and keep their pools algae free in various ways.

1. Prohibit runoff from lawns, landscaping or washing decks from entering the pool;
2. Remove leaves and other rubbish from the pool regularly;
3. Use a phosphate removal treatment;
4. Use a long-life algaecide all year round;
5. Have your pool professional regularly test the pool water for phosphate.

Phosphate removal is the key to keeping pools algae-free, maintaining quality water, and allowing other chemicals to work at their most effective level.

The Langelier Saturation Index (LSI) — based on pH, CH, TA, TDS, and temperature levels — measures water’s tendency to scale or corrode surfaces. Keep your LSI range between -0.3 and +0.3.

Low (or negative) LSI means water is:

• Corrosive
• Aggressive

High LSI can cause:

• Scaling of the pool’s surfaces
• Calcium deposits
• Mineral and metal precipitation

While the LSI is important, it’s more important that the individual factors be in their proper ranges.  Once all the other elements are within range, your LSI should be as well.

One important and often neglected element of water chemistry is Calcium Hardness (CH). Too often, one doesn’t realize that soft water can be corrosive or “aggressive.”  And when it’s considered hard, it’s prone to scaling. Water drawn from wells or deep aquifers tends to have more dissolved calcium (be “harder”), leading to scale. If the CH level is too high (too “hard”), balance can be restored by draining part of the pool water and adding water that is lower in CH. If the CH level is too low, add the appropriate amount of Calcium Hardness increaser.

Pools should always test zero for metals. Unsightly red, blue or green stains could be the result of metallic contamination in the water, and over time they will be difficult, if not impossible, to remove. If you do have a stain or discoloration that you suspect is caused by metals in the water, take a water sample to your dealer so they can prescribe the correct treatment based on the type of metal in your water.

The pH is a measure of the acidity or basicity of your pool water. Maintaining a proper pH level can be just as important as having chlorine in the pool. Chlorine is about 10 times more effective at sanitizing your water when the pH is at 7.2 rather than at a high ph level of, say, 8.2.

The pH level in your pool should be about the same as the pH level of human tears, which is 7.2. A pH level of 7.2 – 7.8 is optimal.

Pool water with a pH below 7.2 is considered to be corrosive and will damage:

• Plaster Finishes
• Paint Finishes
• Vinyl Liners
• Fiberglass Finishes

When pH is allowed to climb above 7.8, it will have a tendency to form calcium carbonate scale on:

• The Pool’s Surfaces
• Interior Plumbing
• Especially Inside Heaters

If your pH level is still off even after adjusting your total alkalinity, add pH+ to increase the pH or muriatic acid to decrease the pH.

Total Alkalinity, or TA, is the measure of the pool or spa water’s ability to resist changes in pH.  The TA acts as a buffer, or control, to keep the pH of your water at industry recommended levels.  If the TA is too low (low alkalinity), the pH can “bounce” and this can adversely affect the water chemistry balance and cause other problems with your pool.

The industry recommended level for TA is 80-120 ppm (parts per million). After testing the water, if you discover that your water chemistry is out of balance, it is very important to adjust the TA first (with alkalinity increaser or pH decreaser), and then adjust the pH if necessary.  Unbalanced alkalinity can lead to serious consequences that could possibly damage your pool.

Symptoms or problems relating to low TA are:

• pH bounce
• Etching or staining of pool/spa surfaces
• Corrosion of metal parts in your pool or mechanical system
• Wrinkles in liner

Symptoms or problems relating to high TA are:

• Cloudy water
• Scale formation
• pH resistant to change/drifts upward

High TA can be tough to bring down and may require you to add a pH decreaser in small increments over a 3-5 day period, retesting the level in one week’s time.

First and foremost, the recommended range for chlorine in a swimming pool is 1 to 4 ppm (parts per million).  Chlorine in pool and spa water may be present in two forms. First, there is free chlorine, which does the hard work of killing bacteria and oxidizing contaminants. (When you add a chlorine compound like Cal-Hypo or trichlor to your pool, you are actually adding free chlorine.) When the free chlorine combines with these contaminants, such as oils, swimmer waste and other organic compounds, it becomes combined chlorine, or chloramines. In pool and spa water, this form of chlorine has very little sanitizing ability, and no oxidizing ability. You can think of combined chlorine as a spent bullet.

Total chlorine is just the sum of both combined chlorine and free chlorine. In other words,

(total chlorine) = (free chlorine) + (combined chlorine)

Knowing your total chlorine and free chlorine levels allow you to calculate combined chlorine (combined chlorine = total chlorine – free chlorine). If the total chlorine level is higher than free chlorine, it is obvious that combined chlorine is present. In that case you need to shock or superchlorinate your pool or spa. To shock the pool, you add a free chlorine compound in an extra large dose. The high dosage of free chlorine will actually oxidize (destroy, burn off) the combined chlorine.

Remember, organic or stabilized chlorine sanitizers will have a neutral to negative effect on pH. Inorganic or unstabilized chlorine sanitizers will cause pH to rise.

1. Remove any plant debris and water from deck and cover.
2. Remove cover, clean it, let it dry and store.
3. Add water up to middle of the skimmer or to the normal operating level.
4. Remove any freeze plugs or other items installed to protect against freezing.
5. Clean your filter (if this was not done when you closed the pool).
6. Start the system up, making sure to prime pump before starting the motor and purge all air from the system.
7. Check for any cracks, holes, and/or tears in the liner or surface of the pool and repair.
8. Remove large debris with a net; vacuum all small debris to waste.
9. DO NOT add any chemicals; first, bring a water sample to the GENCO water lab to check your water chemistry! Adding chlorine and other chemicals in certain circumstances can damage/stain your pool!