Cheapest Way to Heat a Pool Without a Heater

Why Heat Your Pool Without a Heater?

As a homeowner in New Zealand, I love having a pool in the backyard, but I don’t love how chilly the water can get, especially outside of the peak summer months. Pool heaters are an option, but they can be expensive to purchase and run. So, I started looking into the cheapest ways to warm up my pool without using a traditional heater.

If you’re in the same boat, here are some affordable and eco-friendly ways to keep your pool comfortable for longer.

Use a Solar Pool Cover

One of the simplest and most effective ways to warm your pool is by using a solar pool cover (also called a solar blanket). These covers are made from a bubble-wrap-like material that absorbs heat from the sun and traps it in the water, reducing heat loss overnight.

Cost-effective – Prices vary, but you can find solar covers from around $100 to $500 depending on size and thickness.
Reduces evaporation – Less water loss means lower maintenance costs for topping up your pool.
Available locally – Check out NZ retailers like Bunnings and Para Rubber for solar covers.

Liquid Solar Pool Covers

If you don’t want the hassle of a physical cover, liquid solar pool covers are another option. These are chemical-based solutions that create an invisible, heat-trapping layer on the surface of the water.

Easy to use – Just pour the liquid into your pool as directed.
Cheaper than traditional covers – Bottles typically cost between $40 and $100 and last for several months.
Available in NZ – Check with local pool suppliers like Pool & Spa Warehouse for options.

Wind Barriers

Did you know that wind can steal heat from your pool? Creating windbreaks around your pool area can help prevent heat loss and keep your pool warmer.

Options for Wind Barriers:

Plant hedges or tall shrubs – A natural and attractive option.
Install fencing or glass panels – Many NZ homeowners use glass pool fencing, which doubles as a windbreak. Check out suppliers like Glass Vice for ideas.
Use outdoor screens or shade cloth – A flexible and budget-friendly option available from Mitre 10.

Black Hose Trick

A more DIY approach is using a black garden hose to take advantage of solar heat. This works by coiling a long black hose in direct sunlight and circulating pool water through it.

How to do it:

Place a long, black garden hose in a sunny spot or on a dark-coloured roof.
Attach one end to your pool pump system (or simply use a submersible pump).
Allow the sun to heat the water inside the hose before returning it to the pool.

This method is practically free if you already have a hose and a pump, and it can add a decent amount of warmth on sunny days.

Solar Rings or Mats

If you have limited space or don’t want to deal with a full solar cover, consider solar rings or mats instead. These float on the surface, acting like small solar heaters that absorb the sun’s energy.

More flexible than full covers – Easy to put on and take off as needed.
Can be used in conjunction with other methods – A great way to boost overall heat retention.
Available at local shops – Try checking Trade Tested or The Warehouse for solar pool products.

Timing Your Water Circulation

Running your pool pump and filter at the right time can also help retain heat. The best time to circulate your water is during the warmest part of the day, as it helps spread any heat your pool has gained from the sun.

Avoid running your pump at night when the air is cooler.
If you have a pool cover, keep it on at night to trap heat.

Dark Pool Liners or Paint

If you’re planning a new pool or a renovation, consider opting for darker pool liners or paint. Dark colours absorb heat better than lighter ones, naturally keeping your pool warmer.

For existing pools – Look into dark-coloured pool covers if changing the liner isn’t an option.
For new pools – Talk to NZ pool builders like Freedom Pools about darker finishes.

Final Thoughts

Heating your pool doesn’t have to be expensive or bad for the environment. By using solar covers, windbreaks, DIY solar heating, and other simple methods, you can significantly increase your pool’s temperature without relying on a costly heater.

Give some of these techniques a try, and enjoy more swimming time in your backyard!

Pool Owners New Zealand