How to Use a Solar Pool Cover (and Store It for the Season)

Here is how to use a solar pool cover: float it on the water bubble side down, let it relax for a few days, trim it to the shape of the pool, and keep it on whenever nobody is swimming. Before anyone gets in, take it off the water completely, never halfway. When it is off the pool, keep it in the shade, and at the end of the season clean it, dry it, fold it on the seams, and store it somewhere cool, dry, and free of rodents. The steps below follow the makers’ written instructions and the CPSC’s warnings about solar covers.

Safety first: a solar cover is not a safety cover. Blue Wave’s installation and use instructions for its 12 mil solar blanket say the blanket is not a safety device and is not designed to support the weight of a person, that it is possible to drown on top of it, and that it is possible to get caught under it and drown if it is not properly removed before swimming. A CPSC release says non-rigid covers such as solar covers do not provide protection from drowning and can appear to be in place even after children slip underneath them into the water. Remove the cover completely before anyone swims. Blue Wave’s instructions say children should be supervised to make sure the blanket has been completely removed.

Which Side Up: Solar Pool Cover Bubbles Face the Water

The bubbles go down, against the water, and the smooth side faces up. All three maker sources cited in this guide say the same thing:

• Blue Wave’s instructions say the cover is installed with the bubbles facing down and the smooth side up.
• The D.E.I. solar cover warranty and instructions (hosted by Doheny’s) say to place the cover flat on the surface of the water bubble side down.
• In The Swim’s product page for its 12 mil Premium solar cover answers the same question: install with bubble side down on water.

If you cannot tell which side is which, run your hand over it: the bubble side is the one with the rows of raised air pockets. Check this before you trim anything, because the outline you mark depends on it.

How to put a solar pool cover on the first time

A new cover arrives folded and usually larger than the pool, because it is meant to be cut to fit. Read the instructions that came with your own cover first, since steps and limits can differ by maker. The steps below follow Blue Wave’s instructions.

1. Unfold it beside the pool, then float it bubble side down. Lift it over the coping rather than dragging it. Blue Wave says to lift the blanket carefully over abrasive pool decks, coping, or any sharp, ragged surface.
2. Let it float for a few days. Blue Wave says to leave the cover floating for 2 to 4 days to remove the packaging creases before you cut it.
3. Mark the outline. With the cover on the water, trace the pool walls on the cover with a marker.
4. Take the cover out of the pool before you cut. Blue Wave says to remove the cover after making the outline and to trim away from the vinyl liner, because scissors or other cutting tools may damage pool liners. Household scissors cut the cover easily, according to the same instructions.
5. Cut a little large first. Blue Wave says it is better to cut the cover larger than needed, then give it a final trim for an exact fit after a day or two.
6. Skip the tie-downs. Once the cover is cut correctly, Blue Wave says it should not need grommets, ties, or weights, and that bubble side down it should float in place through wind and heavy rain.

Trimming does not have to cost you the warranty: the D.E.I. sheet says its cover can be cut to fit the pool without voiding the warranty. On a 15 ft round above ground pool, the trim is usually a simple circle. On a kidney-shaped inground pool, take your time around the curves and steps, and leave the final trim for the second day as Blue Wave suggests.

Using the cover day to day

The routine is simple: cover on when nobody is swimming, cover completely off when anyone is. The details below are where owners most often slip.

• Never leave it partly on. A 1980 CPSC warning about solar pool covers says swimmers who swim under part of a solar cover risk surfacing into it and being unable to breathe, that swimmers should not enter a pool where a solar cover may be partially covering the water, and urges owners never to leave such a cover partially in place. Pulling the cover halfway back so the kids can swim at the shallow end is exactly the setup that warning describes.
• Do not use it as a surface for people. Blue Wave says the blanket is not designed to support the weight of a person. The same 1980 CPSC warning also reports a pet dog that fell into a swimming pool and drowned beneath a solar pool cover.
• Watch the children, not the cover. Supervise children so you know the blanket is fully off before anyone swims, as Blue Wave’s instructions direct. CPSC’s Pool Safely tips call for an adult Water Watcher, a fence at least four feet high on all sides, and a self-closing, self-latching gate.
• Keep it clean. Blue Wave says a clean blanket is more efficient than a dirty one, to clean it with water and a soft brush, and to dispose of the dirt and leaves promptly after hosing them off the floating blanket.
• Take it off when the pool is shocked. The D.E.I. sheet says to remove the cover when shocking and not to put it back on the water within 8 to 10 hours after super chlorinating. Follow the label on every pool chemical for the water itself; these are rules for protecting the cover.
• Take it off when the water gets hot. Blue Wave says water above 90°F may shorten the blanket’s life and that the blanket should be removed when the pool rises above that. The D.E.I. sheet says not to use the cover above 90 degrees.

Taking the cover off and keeping it out of the sun

Pull the cover off from one end and fold or roll it as it comes out of the water. On a large inground pool, a cover reel can help: In The Swim’s pages say a solar cover reel makes removing and applying the cover more convenient and helps reduce wear and tear.

Where the cover sits while you swim matters more than most owners expect. Blue Wave’s instructions say the blanket must be protected from sunlight when it is off the pool, by placing it in the shade or covering it with a white opaque cover, and that delamination from direct sun while off the pool voids the warranty. The D.E.I. sheet says a rolled or folded cover, on the water or not, must be kept out of the sun. In The Swim says to use a poly tarp or a solar blanket cover over a cover stored on a reel, and to keep a folded cover in a shady area or inside. A cover left in a heap on a sunny deck all afternoon is getting exactly the exposure those instructions warn about.

How to fold a solar pool cover

Blue Wave’s storage instructions are short: clean the blanket, let it dry thoroughly to prevent mildew, fold it on the seams, and roll it from one end. In practice:

1. Spread the cover on a clean, smooth surface such as a lawn, away from sharp edges.
2. Hose off dirt and leaves and brush gently with a soft brush.
3. Let both sides dry completely, out of direct sun as much as you can.
4. Fold it along the seams into a long strip.
5. Roll the strip from one end into a bundle you can carry.

If the cover lives on a reel during the season, the same rules apply at the end of it: clean and dry before you roll it up for the winter, and keep the reel covered or in the shade.

How to store a solar pool cover for the off season

A solar cover comes off when the swimming season ends. Blue Wave says not to leave the blanket on the pool after the season, because it is not a winter cover and winter conditions may severely shorten its life. Choosing a winter cover is a separate decision, covered in mesh vs solid pool cover.

• Clean and dry first. Blue Wave says to let the blanket dry thoroughly to prevent mildew.
• Pick a clean, dry, rodent-free spot. That wording comes from Blue Wave’s instructions.
• Keep it cool. Blue Wave and the D.E.I. sheet both say not to store the cover where temperatures might reach 120°F. If a shed or attic gets very hot in summer, choose a cooler spot.
• Keep the paperwork. Blue Wave’s warranty cards say registration is required to claim coverage, ask buyers to mail the card within 30 days of purchase, and require following the installation and use instructions.

Common problems and what causes them

• Bubbles flaking or breaking. In The Swim’s 8 mil Standard cover page says breaking and flaking of bubble material is not a defect and is caused by acidic water conditions or high chlorine. It is not covered by that warranty.
• Layers separating. Blue Wave’s 8 mil and 12 mil warranty cards both say the only things covered are delamination and seam failure, so contact the maker with your registration if that happens under normal use.
• Faded or degraded cover. Sun damage while the cover is off the pool is excluded from the In The Swim and D.E.I. warranties. Look at where the cover sits during the day.
• Cover drifting or blowing off. Check the fit first. Blue Wave says a correctly trimmed cover should stay in place in wind and rain without ties or weights.
• Creases on a new cover. Give it the 2 to 4 days on the water that Blue Wave’s instructions call for before trimming.

Thickness also changes how a cover handles: thicker covers weigh more and, in the lineups reviewed here, carry longer prorated warranties. If you are still deciding what mil is best for a solar pool cover, weigh how you will take it off the pool before you look at the warranty. You can browse other cover guides in the Pool Covers section.

FAQ

How do you use a solar pool cover day to day?

Keep it on the water, bubble side down, whenever nobody is swimming. Take it off completely before anyone gets in, store it in the shade while it is off, and remove it when you shock the pool or the water rises above 90°F. The specific limits in this guide (2 to 4 days before trimming, the trimming steps, 90°F, and 120°F storage) come from Blue Wave’s instructions and the D.E.I. sheet, so follow the instructions that came with your own cover.

Do solar pool cover bubbles go up or down?

Down. Blue Wave’s instructions, the D.E.I. sheet, and the In The Swim product pages all say to place the cover bubble side down on the water, with the smooth side facing up.

Can you swim with a solar cover partly on the pool?

No. The CPSC says swimmers should not enter a pool where a solar cover may be partially covering the water, and Blue Wave’s instructions say the blanket must be removed before swimming. Take it all the way off.

Can I leave a solar cover on the pool over the winter?

No. Blue Wave says its solar blanket is not a winter cover and that winter conditions may severely shorten its life. Clean it, dry it, and store it somewhere dry and rodent-free, below the 120°F limit in Blue Wave’s instructions and the D.E.I. sheet, then use a winter cover on the pool.

Do I need weights or ties to hold a solar cover in place?

Usually not. Blue Wave’s instructions say a correctly cut cover, bubble side down, should float in place through wind and heavy rain without grommets, ties, or weights. If yours keeps moving, recheck the trim.

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