Our neighbour’s solar blanket lasted one Melbourne summer before it started flaking blue bits into the water every time the wind picked up. She’d bought the cheapest one she could find online, no roller, folded it in half to store it, and by January it looked like confetti. That’s basically the whole reason to read a guide like this before you buy — a pool cover is one of those things where the cheap option costs you more in year two.
If you’re comparing a pool cover solar blanket 600 micron against the thinner 500 micron versions, or trying to work out what roller width actually fits your pool, here’s what genuinely matters.
What does “600 micron” actually mean?
Micron refers to the thickness of the plastic film, measured in thousandths of a millimetre. A 600 micron blanket is roughly 20% thicker than a standard 500 micron one. That extra thickness means:
- Better heat retention — the bubble cells trap more warmth and hold it longer overnight
- More UV resistance, so the material doesn’t go brittle and crack as fast in harsh Australian sun
- A bit more weight, which actually helps it sit flatter on the water instead of curling at the edges
The trade-off is price and a slightly heavier roll to wind up. For most family pools that get used from October through to April, 600 micron is the sweet spot between longevity and value. If you’ve only got a small budget or a shaded pool that doesn’t cop full sun all day, a 500 micron blanket like the Pool Cover 7x4m 500 Micron Solar Blanket with Aluminium Roller 5.5m Width will still do the job and costs less upfront.
Getting the size right — this is where people stuff it up
A 7m x 4m cover is one of the most common sizes for rectangular in-ground pools in Australia, but “close enough” doesn’t work with solar blankets. Too small and you lose heat retention and evaporation control at the edges. Too big and you’re trimming plastic bubble sheet with scissors in your backyard, which is nobody’s idea of a Saturday.
Before ordering, measure:
- The waterline length and width, not the coping or paving edge
- Any steps, ledges or spa sections that might need the cover trimmed around them
- The clearance beside your pool for a roller — you need at least the roller’s length plus 30-40cm to actually wind it up comfortably
The Pool Cover Solar Blanket 600 Micron 7x4m with Aluminium Roller 5.55m Adjustable comes with a roller that adjusts, which is genuinely useful if your pool is closer to 6.8m or you’re not 100% sure of the exact width yet. It gives you a bit of forgiveness without the roller looking like it’s swimming in itself.
Why bother with a roller at all?
You can absolutely fold and store a solar blanket without one, but here’s what happens over a season: constant folding along the same creases weakens the bubble cells exactly where you fold them. Within a year you’ve got permanent flat lines running across the cover where it’s lost its insulating pocket of air. A roller means the cover stores in one smooth curve, no crease damage, and honestly it takes about 90 seconds to wind on or off instead of wrestling a wet, heavy sheet across the pool deck by hand.
Aluminium rollers specifically matter because they don’t rust or seize up the way some cheaper coated steel options do after a few wet seasons near a saltwater pool.
Adjustable roller vs fixed crank — what’s the actual difference?
Some rollers are a simple adjustable tube system, others come with a crank handle for winding, sometimes in a two-tone finish like the Pool Cover 7x4m 600 Micron Solar Blanket with Aluminium Roller Crank Black Blue. A crank handle just makes winding smoother, particularly if the pool cover is on the heavier end (thicker micron covers do add weight) or if the person usually rolling it up isn’t especially strong. If you’ve got kids or an older family member handling pool maintenance, the crank version is worth the small extra cost for how much easier it makes the daily routine.
Quick comparison at a glance
- 500 micron, 5.5m roller — good entry option, lighter to handle, decent heat gain for casual use
- 600 micron, 5.55m adjustable roller — better durability and heat retention, adjustable roller suits slightly uncertain measurements
- 600 micron with crank roller — same durability, easier winding mechanism, good for daily use households
Will it actually cut your heating bill?
Solar blankets work by trapping solar heat during the day and slowing evaporation overnight — evaporation is the single biggest source of heat loss in an outdoor pool. A well-fitted 600 micron cover can lift water temperature by 4-8°C over a season compared to an uncovered pool, and cut evaporation (and therefore water and chemical top-ups) by up to 95% when it’s on consistently. The catch is “consistently” — a cover sitting folded in the shed doesn’t heat anything. This is exactly why the roller matters so much for real-world use: if it takes two minutes to roll on after the kids finish swimming, it actually gets used every single day instead of every second weekend.
Looking after it so it lasts
- Rinse off leaves and debris before rolling it up — trapped organic matter breeds algae on the underside
- Keep it off hard pavement in direct sun when not in use; UV exposure without water contact ages the plastic faster
- Check pool chemical levels stay within normal range — very high chlorine or low pH speeds up degradation of any solar cover, regardless of micron thickness
- Store bubble-side down on the water always, never bubble-side up
For a 7x4m pool that gets regular family use through summer, the 600 micron option with an adjustable aluminium roller is the one we’d point most Melbourne households toward — it strikes the right balance of heat retention, durability and ease of use without tipping into commercial-grade pricing. If your pool sits mostly in shade or you’re covering a smaller budget this season, the 500 micron version is a perfectly reasonable place to start, and you can always upgrade thickness next time round.