Clear vs blue solar covers
The difference is where the energy lands, not how much of it arrives. Which turns out to matter less than the marketing suggests.
Quick picks
One of each, because the honest verdict is that the difference between them is smaller than the difference in how long they last.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | No photo Best clear Sun2Solar 1200 Series Crystal Clear Solar Cover Transmits more into the body of the water instead of stopping it at the surface. | Most pools, most budgets — the default recommendation | |
| 2 | No photo Best blue Sun2Solar 1600 Series Ultimate Blue Solar Cover If you prefer not to see the pool floor through the cover, this is the one to buy. | An inground pool you cover most nights, every season |
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked September 2, 2026.
The physical difference
The same amount of sunlight lands on your pool whatever color the cover is. NASA’s energy budget does not care about your purchasing decisions. What changes is where that energy ends up.
A clear cover transmits. More light passes through the film and is absorbed by the water column below, including by the pool floor, which re-radiates it into the water. Bob Vila’s summary is the standard one: “Clear solar covers allow a lot of pool-warming sunlight to pass through.”
A blue or dark cover absorbs. More of the energy is taken up by the film itself, which then conducts it into the water it is touching. The same page notes that “dark solar covers block a large portion of UV radiation” — which is a genuine secondary effect, since UV is what degrades your chlorine.
The measured difference
Here is the part that ought to settle the argument. In the only published hands-on comparison in this category, the group included both a 12-mil clear cover and a 16-mil blue one, and the reported result was that “each of the pool covers increased the temperature 4 to 5 degrees Fahrenheit”.
Clear and blue, in the same test, an hour each, same conditions: indistinguishable within a one-degree band. Whatever the theoretical difference in where the energy lands, it did not show up as a difference in the water temperature.
The reasons to actually pick one
Since heating is not a strong discriminator, pick on the things that are:
- Thickness comes bundled with color at retail. This is the practical one. Blue covers dominate the thin end of the range and clear covers dominate the thick end — published tiers put blue at 4 and 8 mil and clear at 12 and 16 mil. If you are buying on service life, you are largely buying clear by default. The thickness comparison is the more consequential decision.
- UV and chlorine. A dark cover blocking UV means less chlorine burned off by sunlight. DOE puts the chemical saving from covering a pool at 35 to 60% generally; a dark cover is at the helpful end of that.
- Algae and appearance. A clear cover lets light reach the water, which is exactly what algae wants. On a pool with marginal chemistry, blue is the safer choice. A clear cover also shows every leaf and every bit of debris.
- Heat at the deck. A dark cover in full sun gets hot to touch. If children are around the pool edge, that is worth knowing.
Our verdict
Buy on thickness and fit; treat color as a tiebreaker. For most pools that lands you on a 12-mil clear cover, which is our overall pick anyway. Choose blue if you have had algae trouble, if you want the UV-blocking benefit for chemical costs, or if you simply do not want to see the pool floor through the cover.
What you should not do is pay a premium for one color expecting warmer water. The published measurement does not support it and the physics does not predict it.
Every pick, in detail
What each one publishes, what is good and bad about it, and — the section this category usually omits — what we could not judge without owning one.
Sun2Solar 1200 Series Crystal Clear Solar Cover
The value pick, and the one whose logic actually holds up. A clear cover transmits more sunlight into the body of the pool instead of absorbing it at the surface, and 12 mil is the point where lifespan stops being the limiting factor. Bob Vila measured this and the 16-mil blue at the same 4 to 5 degrees in an hour, so you are paying less for the same measured result and giving up some years of service life.
Best for Most pools, most budgets — the default recommendation
| Thickness | 12 milThe manufacturer publishes no retrievable specification sheet; figure is as listed at retail. | Retail listing |
|---|---|---|
| Color | Clear | Retail listing |
| Stated lifespan | 3 to 4 years for the 12-mil clear tierSwim University's published figure for 12-mil clear covers generally. | Retail listing |
| Bubble side | Bubbles face the water | Published standard |
4 to 5 degrees F in one hour
Claimed by Bob Vila, measured across all covers in their group. Conditions: One hour under 2pm sun on 89 to 92 degree F days. Source
- Clear transmits more light into the water instead of stopping it at the surface
- 12 mil is the sweet spot: real service life without 16-mil bulk
- Cheaper than the 16-mil tier with no measured heating penalty
- Shorter published lifespan tier than 16 mil
- A clear cover shows algae and debris more obviously, which some people dislike
- Whether clear genuinely outlasts or under-lasts blue in the same thickness
- Real-world tear resistance at a pool with rough edges
- How much the clear material clouds over a season of UV
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked September 2, 2026.
Sun2Solar 1600 Series Ultimate Blue Solar Cover
The cover to buy if you intend to keep using it in five years. 16 mil is the thickest tier the category sells, and thickness on a solar cover buys durability rather than heat — Bob Vila measured every cover in its hands-on group at the same 4 to 5 degrees, from 12-mil clear to 16-mil blue. Pay the extra for the one that survives being dragged over the coping twice a day, not for a temperature difference that did not show up in the only published one-hour test in this category.
Best for An inground pool you cover most nights, every season
| Thickness | 16 milThe manufacturer publishes no retrievable specification sheet; figure is as listed at retail. | Retail listing |
|---|---|---|
| Color | Blue | Retail listing |
| Stated lifespan | 5 to 10 years for the 16-mil tierSwim University's published figure for 16-mil covers generally, not a Sun2Solar warranty statement. | Retail listing |
| Bubble side | Bubbles face the waterCategory-wide instruction, not brand-specific. The bubbles are the insulating layer and they have to touch the water. | Published standard |
4 to 5 degrees F in one hour
Claimed by Bob Vila, measured across all covers in their group. Conditions: One hour under 2pm sun on 89 to 92 degree F days. Source
Their figure was the same for every cover they put on the water. Read our reconciliation of what a one-hour reading actually measures before you plan around this number.
- Thickest tier sold, which is where the durability difference actually is
- Blue absorbs more of the incoming energy at the surface than clear does
- Cuts oversize to your pool shape with household scissors
- Heavy and awkward at 16 mil — a large inground cover is genuinely a two-person job without a reel
- Costs meaningfully more than the 12-mil version for no measured heating advantage
- Whether the seams hold up over five seasons of daily handling
- How the bubble layer survives repeated dragging over rough coping
- Whether the stated lifespan tier holds for this specific product line
These need a unit in hand across a season. We do not have one, so we do not have an opinion worth printing on them.
#ad We earn a commission if you buy through this link, at no extra cost to you. It never changes the ranking. How this site is funded. Prices last checked September 2, 2026.
Questions people actually ask
Is a clear or blue solar cover better?
Do clear solar covers cause algae?
Does a dark solar cover save chlorine?
- U.S. Department of Energy pool-energy figures (evaporation share, BTU per pound evaporated, cover savings, recommended temperatures, wind effect)Recreonics, reproducing and attributing the U.S. Department of Energy · read 2026-09-02
- U.S. Department of Energy, Energy Saver: Swimming Pool Covers (archived — the live page now returns 404)U.S. Department of Energy via the Internet Archive · read 2026-09-02
- Hands-on solar cover comparison: 4 to 5°F measured in one hour of 2pm sun on 89–92°F days, with the method statedBob Vila · read 2026-09-02
- Solar cover guide: 0.7°F per hour under noontime sun, 10–15°F held, and published lifespan tiers by thicknessSwim University · read 2026-09-02
- Water density: 62.424 pounds per cubic foot at 39.2°FU.S. Geological Survey, Water Science School · read 2026-09-02
Every URL above was fetched and returned content on the date shown. Where a figure is ours rather than somebody else’s, the arithmetic is on the page and on the methodology page. If you find an error in it, we would genuinely like to know.
Read next
8, 12 or 16 mil: which solar cover thickness
Thickness buys years, not degrees. The published lifespan tiers, the cost per year of service, and the case for 12 mil on a large pool.
Solar pool covers worth buying
Ranked on the specifications that actually differ between covers — thickness tier and published lifespan — because the only hands-on test in this category found no heating difference at all.
How a solar cover heats a pool
Transmission during the day, evaporation suppression at night. The two mechanisms separated, with the energy arithmetic for each.
Do solar pool covers work?
The 4-degrees-versus-15-degrees contradiction that runs through this entire category, reconciled from published physics. Three different quantities being reported as one.