📚 Deep-dive guides

Only needed where water can freeze. In warm climates, keep the pump running and watch for freeze warnings. Always follow your equipment and cover manufacturers' instructions.

1. Balance the water and add a winterizing chemical kit about a day or two before closing.
2. Clean the pool thoroughly: skim, brush, vacuum, and clean the filter.
3. Lower the water to the level your cover type calls for.
4. Blow out the plumbing lines with a compressor and plug them (or use pool antifreeze where recommended).
5. Drain the pump, filter, heater, and chlorinator so no water is left to freeze and crack them.
6. Remove ladders and accessories, then secure a clean cover.

Learn more: Opening your pool in spring ›

Learn more: Winter chemicals and borates ›

A salt system doesn't make a chlorine-free pool. A cell converts dissolved salt into chlorine, so you get steady, gentle sanitizing.

• Keep salt in the range your cell manufacturer specifies (commonly around 2,700–3,400 ppm).
• You still need to test free chlorine, pH, alkalinity, and stabilizer.
• pH tends to drift upward, so expect to add acid regularly.
• Inspect the cell for white scale a few times a year and clean it per the manual.
• Salt can harm some natural stone, metal fixtures, and decking, so ask a pro before installing.

Learn more: Caring for a salt water pool ›

Learn more: Salt cell care and replacement ›

1. Test and fix pH first (around 7.2–7.4) so chlorine works better.
2. Remove debris, brush every surface, and clean the filter.
3. Run the pump nonstop and shock heavily, using the product label and your stabilizer level to choose the dose.
4. Brush often, retest, and re-shock until the water is clear and the chlorine level holds steady overnight.
5. Clean or backwash the filter repeatedly. It will clog with dead algae.
6. Once clear, return to your normal routine and find out why it turned green (low chlorine, poor circulation, or heavy rain).

Learn more: Preventing algae ›

Learn more: Cleaning up after a storm ›

1. Test free chlorine, pH, alkalinity, and stabilizer.
2. Bring pH to about 7.2–7.6 and chlorine to 1–3 ppm. Shock if the water smells of chlorine or is dirty.
3. Brush the walls and floor so fine particles reach the filter.
4. Run the pump around the clock until the water clears.
5. Clean or backwash the filter and note the pressure afterward.
6. Use a clarifier only as the label directs. Flocculants settle debris, so you must vacuum it to waste.
7. For foam, skim it off, check for algaecide overuse, and shock if organics are high.
8. Still cloudy after about three days? Have a pro test the water and inspect the filter media.

1. Test with a fresh, reliable kit. Change one thing at a time and retest after the water circulates.
2. Alkalinity first: aim for about 80–120 ppm, because it steadies pH.
3. Then pH: above 7.6, add acid in small doses; below 7.2, add a pH increaser. Always follow the product label.
4. Stabilizer (CYA): aim for about 30–50 ppm. If low, add stabilizer per the label and retest in a day or two, since it dissolves slowly. If it is far too high, a partial drain and refill is the usual fix.
5. Chlorine: keep free chlorine at 1–3 ppm. A strong chlorine smell means chloramines, so shock per the label and retest.
6. Retest in 24 hours and log your readings to spot trends.

1. Test calcium hardness, pH, alkalinity, and water temperature. Scale forms when these run high.
2. Lower pH and alkalinity into range. If calcium is well above about 400 ppm, a partial drain and refill helps.
3. Light scale on tile: scrub with a pool-safe scale remover for your surface. Heavy scale usually needs a pro.
4. For stains, test a small spot: rub a vitamin C (ascorbic acid) tablet on it. If the stain brightens, it is likely metal. If not, it is likely organic, such as leaves.
5. Metal stains: use a stain remover and a metal sequestrant as labeled, then keep water balanced.
6. Organic stains: brush and shock.
7. Check your fill water and equipment for the metal source if stains return.

1. Brush the affected areas hard. Use a stainless brush only on plaster, never on vinyl or fiberglass.
2. Raise chlorine to shock level and keep the pump running.
3. Spot-treat black spots only as the product label directs for your surface.
4. Clean skimmer baskets, ladders, toys, and gear, since pink slime hides there and returns.
5. Clean the filter after the treatment.
6. Brush daily for a week, keep chlorine steady, and retest. If it keeps returning, ask a pro to check circulation.

1. Bucket test: set a bucket filled to the pool level on the first step. Mark the water level inside and outside the bucket.
2. Run the pump for 24 hours and compare drops. Then repeat with the pump off.
3. If the pool drops more than the bucket, you likely have a leak. If it drops only with the pump on, suspect pressure-side plumbing. If it drops with the pump off too, suspect the shell, fittings, or suction side.
4. Look around the equipment pad for drips, wet ground, and leaking unions, valves, or seals.
5. Turn the pump off and drop a little dye near suspected cracks or fittings to see if it is pulled in.
6. Check for an automatic fill valve that may be hiding a leak.
7. Call a leak detection pro for pressure testing.

Turn the pump off at the breaker before opening anything.

1. Confirm the water level is at least at the middle of the skimmer opening.
2. Empty the skimmer and pump baskets and open all valves.
3. Clean the lid o-ring and lubricate it with a silicone-based lubricant, then seat the lid firmly.
4. Fill the basket with water, close the lid, and restart. Lots of bubbles means air is entering on the suction side. Check unions, drain plugs, the lid o-ring, and the skimmer.
5. Low flow: check for a clogged impeller and a dirty filter.
6. Noise: grinding means bearings, humming with no spin points to a stuck impeller or bad capacitor, and rattling or gurgling points to low water or blocked suction.
7. Turn it off if it grinds, never run it dry, and call a pro for motor, seal, or bearing work.

Turn the pump off before changing any valve position.

1. Note the current pressure and compare it with the clean reading.
2. Cartridge: open the air relief, remove the cartridge, hose between the pleats top to bottom, soak in cartridge cleaner if oily, rinse, and reinstall with the o-ring seated.
3. Sand: set the valve to backwash and run until the sight glass clears (about 2–3 minutes), then rinse about 30 seconds, then return to filter.
4. DE: backwash, then recharge with DE per the manual.
5. Restart the pump, release trapped air, and record the new pressure.
6. If pressure climbs quickly again or the media is worn, replace it or ask a pro.

1. Set the thermostat above the current water temperature and confirm the heater is on.
2. Make sure the pump is running and filter pressure is normal. Low flow stops heaters from firing.
3. Gas heater: confirm the gas valve is on and the supply (or propane tank) is available. Watch the display for a fault code.
4. Heat pump: clear debris from around the unit and give it time. Output drops in cool weather.
5. Check the breaker.
6. Write down any fault code and call a pro. If you smell gas, leave the area and call the gas company.

1. Read the message on the display, such as low salt, no flow, or check cell.
2. Test salt with an independent test and compare it with your manual's range.
3. Check flow: baskets, filter pressure, and pump speed. Many cells need enough flow to run.
4. In cold water, many cells reduce output or show false low salt.
5. Inspect the cell for white scale and clean it only as the manufacturer directs.
6. Reset at the breaker per the manual.
7. If errors persist, the cell may be near end of life. Keep chlorine up with liquid chlorine or tablets and call your pro.

1. Robotic: clean the filter basket, untangle the cable, check the swivel, wheels, and tracks, and confirm the water level.
2. Suction or pressure cleaner: check hose connections, the skimmer or wall fitting, and empty the baskets and bag.
3. Confirm pump speed and flow are high enough for your cleaner.
4. Look for worn parts, cracked hoses, or air leaks.
5. Adjust hose length so it reaches all areas without kinking.

1. Check whether a breaker or GFCI tripped and reset it once.
2. If it trips again or right away, stop and call a licensed electrician or pool pro. Do not keep resetting it.
3. Keep your hands dry and stay away from equipment that is wet or sparking.
4. Check the time clock, app schedule, and automation panel (including service or freeze modes).
5. Make sure the pump lid is tight and valves are open. Heater flow switches can also stop equipment.
6. A burning smell, sparks, or a tingling feeling means turn the power off at the main and call a pro right away.

Basic color-comparator kits, with colored blocks for chlorine and pH, are easy to use but limited.

1. Rinse the vial with pool water and take a sample from about elbow depth, away from the skimmer and returns.
2. Add the exact number of drops or tablets your kit calls for, cap, and mix gently.
3. Compare to the color blocks in daylight against a white background, out of direct sun, and read right away.
4. Match the closest block and write down the result with the date.

Know the limits:

• These kits read total chlorine and pH only. They cannot separate free chlorine from combined chlorine
• Very high chlorine can bleach or distort the colors
• pH color tests cover a limited range, roughly 6.8 to 8.2
• Alkalinity, calcium, and stabilizer need separate tests
• Reagents expire, so replace them about once a year

For better accuracy, use a DPD drop kit or photometer for free chlorine, or ask your pool pro to run a full test.

• Flow order: skimmer and main drain, then pump, then filter, then heater, salt cell, or chlorinator if you have one, then back through the returns
• Pump: pulls water through the system. Check the basket and lid o-ring
• Filter: traps debris. The pressure gauge tells you when to clean it
• Heater or heat pump: warms water only when flow is good
• Salt cell or chlorinator: adds sanitizer
• Valves: suction valves choose the skimmer or main drain, return valves choose where water goes back, and the filter valve sets filter, backwash, rinse, waste, or closed
• Controls: breaker, time clock, or automation panel

Safe habits: turn the pump off before changing a filter valve, never run the pump with all suction valves closed, write down your normal pressure, and photograph the pad with labels on the valves.

• Free chlorine is the active sanitizer that kills bacteria and algae. Most pools aim for about 1 to 3 ppm, and higher right after shocking
• Combined chlorine is chlorine that has already bound to waste. It causes the strong smell and eye irritation. Above about 0.5 ppm, shock the pool
• A DPD kit measures free and total chlorine, and the difference is combined chlorine. A basic color kit shows total only
• Chlorine falls with sun, heat, swimmers, rain, and algae
• To raise it, add chlorine as the label directs, such as liquid, granular, or tablets in a feeder. Evening is the best time
• If it is very high, wait for it to fall before swimming
• Stabilizer decides how long chlorine lasts in sunlight

• pH measures how acidic or basic the water is. Aim for about 7.4 to 7.6, and 7.2 to 7.8 is acceptable
• Low pH is acidic. It irritates eyes and skin, corrodes metal, and etches plaster
• High pH makes chlorine weaker and leads to cloudy water and scale
• Trichlor tablets lower pH. Liquid chlorine, salt systems, and splashing or waterfalls raise it
• To lower it: check alkalinity first, add a small dose of pool acid with the pump running, circulate, and retest
• To raise it: add a pH increaser per the label
• Never mix chemicals, and add acid to water, not water to acid

• Alkalinity is the buffer that keeps pH from swinging. Aim for about 80 to 120 ppm
• Too low: pH bounces up and down and water can etch surfaces
• Too high: pH keeps drifting up and scale forms
• To raise it, add an alkalinity increaser (baking soda based) slowly as the label directs, and wait for it to circulate
• To lower it, add acid in small doses, then aerate to bring pH back up without raising alkalinity much
• Adjust alkalinity first, then pH, and retest between steps

• Stabilizer (cyanuric acid) shields chlorine from sunlight. Most pools aim for about 30 to 50 ppm
• Too low: sunlight burns chlorine off in hours
• Too high: chlorine works slowly and algae can take hold even with a chlorine reading
• Stabilized chlorine tablets and granules add stabilizer over time, so it creeps up
• Salt systems still need stabilizer
• There is no chemical to lower it. A partial drain and refill is the usual fix
• Test it every month or two

1. Test chlorine and pH two or three times a week in summer, and once a week in cool weather
2. Skim the surface and empty the skimmer and pump baskets
3. Brush the walls, steps, and corners, then vacuum if needed
4. Check the water level is at the middle of the skimmer opening
5. Look at the filter pressure gauge and clean the filter when it rises about 8 to 10 psi above its clean reading
6. Check the pump runs long enough to circulate all the water at least once a day. Many pools run 8 to 12 hours in summer
7. Refill chlorine feeders or add chlorine as needed
8. Write down your readings so you can spot trends

Test more often after storms, heavy use, or heat waves.

• A pro cuts out the old mastic completely, cleans and dries the joint, sets backer rod where the joint is deep, applies a flexible sealant rated for pool decks, and tools it smooth
• The joint must be dry and the weather dry. Rain or moisture ruins the bond
• Cost depends mostly on how many feet of joint you have and how deep and wide the joints are
• Small areas can be a DIY job with the right product and careful prep. Large or deep joints are best left to a pro
• Ask which product they use, how they prepare the joint, and what warranty they give
• Check the joints every year so small gaps get fixed before water gets under the deck

• A pro will lower the water, tap every tile, check the grout and the bond beam, and note any moisture
• Replacing a few tiles works for isolated damage when the surrounding tile is sound and a match is available
• Replacing the whole band makes sense when hollow areas are widespread, repairs keep failing, or the tile cannot be matched. Coping or deck work often exposes the tile anyway
• Ask for the cause of the damage, photos of the hollow areas, a price for both options, the timeline, and the warranty
• Expect the water level to be lowered and curing time before the pool is refilled to the waterline
• Fixing the cause, such as failed joints or water behind the tile, matters as much as replacing the tile

• Coping is the cap along the pool edge. Do not lean or sit on loose pieces, and keep children away
• Common causes: a failed mortar bed, a cracked or moving bond beam, freeze-thaw damage, soil settling, and failed joints
• Take photos and mark the loose pieces
• A pro can reset coping on a sound mortar bed or replace cracked pieces
• Ask them to check the tile below and the expansion joints, since problems often travel together
• Do not wait. Water behind coping speeds up damage

1. Before winter, re-seal deck joints and repair cracks and loose tile
2. Fix drainage so water runs away from the pool and deck
3. Winterize the plumbing and equipment as your climate requires
4. Keep the winter water level your cover type calls for
5. During winter, pump water and clear debris off the cover and watch for ice
6. In spring, inspect for new cracks, lifted tile, loose coping, or heaved deck

Water expands about 9 percent as it freezes, so any water trapped in cracks or joints can break materials as it freezes and thaws.

• Signs: soggy or sunken ground, cracking or heaving deck, damp stains, patches of lush growth, and a pool that keeps losing water
• Do the bucket test to see whether the pool is leaking, with the pump on and then off
• Check the equipment pad for drips and wet ground
• Look at deck joints and tile for gaps that let water in
• Check drainage: gutters, downspouts, and sprinklers should not send water toward the pool or deck
• Call a leak detection pro if the test points to a leak. Fixing it early prevents soil washout and settling

• Signs it is time: roughness, widespread staining or etching, flaking, and hollow-sounding spots
• Poor water balance shortens the life of the finish. Fixing the chemistry first helps the new surface last
• Resurfacing means draining, preparing the surface, applying a bond coat and the new finish, and refilling quickly
• Ask your pro about groundwater before draining. Emptying an inground pool can damage it, and a hydrostatic relief valve may be needed
• Ask about finish options, the startup plan, and the warranty
• Expect careful brushing and chemistry control for the first few weeks

• Hairline cracks are common and can be sealed
• Have a pro look at cracks that are wide, growing, uneven (one side higher), or that let water pool
• Water that sits near the pool or runs toward the house can cause settling and trip hazards
• Fixes include sealing joints, regrading or adding drainage, and lifting or replacing sunken slabs
• Keep sprinklers and downspouts from soaking the deck edge
• Mark trip hazards and fix them quickly

1. Walk the deck joints and look for cracked, missing, or shrunken mastic
2. Tap tiles with a screwdriver handle and listen for hollow sounds
3. Check coping by pressing gently for movement and looking for gaps
4. Look for new deck cracks, heaving, and pooling water
5. Check the plaster by hand for roughness, stains, and hollow spots
6. Look around the equipment pad for drips and corrosion
7. Take dated photos and keep a simple log so you can compare year to year
8. Share the photos with your pro when something changes

• Red, burning eyes and a strong smell usually mean chloramines, which form when chlorine meets sweat, oils, and other waste
• pH far from 7.2 to 7.8 also irritates eyes and skin
• Fix it by testing, shocking as the label directs, balancing pH, and running the filter
• Rinse off before swimming to cut down on waste
• Dry skin can come from very high chlorine or high or low pH
• Green hair usually comes from copper or other metals in the water, not from chlorine itself

1. Pump off the cover water, brush off debris, then remove the cover. Clean, dry, and store it
2. Refill the pool to the middle of the skimmer opening
3. Reinstall plugs, return fittings, ladders, and accessories, and reconnect equipment
4. Check o-rings, prime the pump, start the system, and look for leaks
5. Run the pump and clean or backwash the filter
6. Test and balance in this order: alkalinity, pH, stabilizer, then chlorine
7. Shock if the water is cloudy or green, then brush and vacuum
8. Keep the pump running around the clock until the water is clear, and retest after a day

• Clean and balance first: pH about 7.2 to 7.6 and alkalinity about 80 to 120 ppm
• Shock a few days before closing, after sundown, and let chlorine fall before adding algaecide
• Add a stain and scale preventer, then winter algaecide last, as each label directs
• Borates act as an algaestat and pH buffer. The common target is 30 to 50 ppm and it should not exceed 50 ppm. Add them to clear water in stages
• Never pour antifreeze into the pool water, and never mix chemicals
• Close when the water is cool, so winter chemicals are not used up quickly

Read the blog post on winter chemicals for the full closing order.

• Test salt monthly with an independent test and compare it with your manual range
• Keep pH in range. It tends to rise, so expect to add acid
• Keep stabilizer in range, since salt systems still need it
• Adjust the output setting for the season and bather load
• Check the cell for white scale every few months and clean it only as the manual directs
• Check flow, baskets, and filter pressure
• Keep backup chlorine on hand in case the cell stops
• In cold water, many cells reduce output or shut off, so follow your manual

• Scale looks like white flakes on the plates and comes from high pH or calcium. Fix the balance so it does not return
• Clean only as the manufacturer directs. Over-cleaning wears the plates
• Cells wear with operating hours, and life varies by model and water balance
• Signs of the end of life: low output even with correct salt, flow, and a clean cell, plus repeated error messages
• Rule out low salt, low flow, and cold water before replacing
• Keep your install invoice and registration, since warranties often limit both time and hours

1. Keep free chlorine high enough for your stabilizer level, and keep pH about 7.2 to 7.6
2. Run the pump long enough to circulate all the water daily
3. Brush weekly, especially steps, corners, and shady spots
4. Empty baskets and clean the filter when pressure rises
5. Shock after storms, heavy use, and heat waves
6. Remove leaves and debris quickly and rinse toys and gear
7. Consider an algaestat such as borates as a prevention layer, following the label
8. Keep a test log so small changes do not turn into green water

1. Check equipment first. If the pad flooded, keep the power off and call a pro
2. Remove large debris by hand and empty the skimmer and pump baskets
3. Test the water before adding anything
4. Fix pH, then shock as the label directs
5. Brush everything and run the pump around the clock
6. Clean or backwash the filter often while the water clears
7. Do not drain a pool in a hurry. High groundwater can damage an empty pool, so ask a pro first
8. Call a pro if the water stays dark or sludgy after several days