How to Heat up a Pool Fast Without a Heater

If you have the ability to heat your pool, then you can start pool season early or even extend it by a month or so by keeping the water warmer than it normally is.

However, heating your pool with the traditional options, such as with a heat pump, propane, or gas can be very costly. Is there perhaps another way to heat your pool up quickly but on a budget?

Indeed, there are some creative ways you can heat your pool for cheap, and as fast as you can without a heater. For instance, you could use solar covers, solar rings, liquid pool covers, the black hose trick, black pool tiles, solar mats, and more to get the job done. Depending on which solution you pick, it will take several hours to days without a heater, but once your pool is warmed up, you can use the solar cover to trap the heat until the next day so that your pool water is always warmer than usual.

In this article, we will explore the various options you can use to heat your pool without a heater. Some require a bit of DIY work, but nothing the average person can’t handle.

How the color black can help you heat up your pool

Before we begin, I want to first talk about the color black.

For those of you who don’t know, the color black can absorb the most light out of all the other colors. That means that anything that is covered in black will be noticeably warmer than objects of a different color.

You probably know this to be true based on experience, but if not, then you can easily test this out yourself.

Try wearing a black T-shirt and stand in the sun for 10 minutes, and compare that to how it feels wearing a white T-shirt, which reflects the most light. The black T-shirt will feel much warmer than the white one.

Not convinced? Try sitting in a black car compared to sitting in a white car. Heck, just place your hand on the hood of a black car compared to the hood of a white car on a sunny day. Careful, you might burn your hand. Or you can watch this video:

The difference in temperature between a black surface and a surface of a different color is substantial, and we can use this knowledge to help us heat our pool fast without a heater.

Black solar cover

A regular pool cover can help keep your pool warmer by keeping evaporation, and heat loss by extension, to a minimum over the course of the day and overnight.

A solar pool cover goes one step further and lets sunlight pass through it to reach the water. Solar covers also have small air pockets on one side that look like bubble wrap that captures heat and transfers it to the water.

By simultaneously preventing evaporation and transferring heat to your pool water, you can raise the water temperature as much as 10-15°F after consecutive sunny days.

Another major benefit of a solar cover is its insulating ability. It can trap heat and keep your pool warm overnight until the next morning, where sunlight will continue to heat the pool.

Essentially, once the pool has been heated up, you can maintain a higher temperature as long as you put the solar cover back on at night or whenever the pool is not in use.

Solar rings

An alternative to solar cover is to cover the surface of your pool with solar rings. Solar rings are heat absorbing rings that are approximately 6 feet in diameter.

When you group solar rings together, they can cover a large portion of your pool and heat it up by transferring the heat it absorbed. Solar rings also reduce evaporation, but not to the same degree as a solar cover.

Additionally, solar covers are more efficient at heating the water (though not very quickly), but the major benefit of solar rings is that they are easier to place and remove than a solar cover. That said, if you have a rectangular shaped pool, you could install a reel system for your solar cover to make placing and removing it easier.

Black garbage bags

Are solar covers and solar rings out of your price range? We can go even more budget-friendly. You can achieve a similar effect as a solar cover by covering the surface of your pool with black garbage bags.

The black material will absorb plenty of sunlight and transfer that energy to your pool water. It also acts as a barrier that prevents water from evaporating.

You can float the trash bags by themselves or you can drape them over pool noodles or any other buoyant object. Ideally, you should use extra thick garbage bags for best results.

The black hose trick

Purchase 100 to 150 feet of black garden hose. Keep it coiled up near the pool so that it can soak in as much sunlight as possible. Let it heat up until it is hot to the touch.

Next, connect one end of the hose to your pool’s pump, or a pump set to pull water out of the pool. Place the ther end in the pool.

As the pump pulls the cold water out of your pool and pushes it through the hot hose, the heat will transfer to the water and it will come out the other end as warm water.

The longer your black garden hose is, the more surface area is available to absorb and store heat that will warm up the water that passes through it.

DIY wood-fired pool heater

Another method that is similar in concept to the black hose trick, but requires more DIY work, is making your own wood-fired pool heater.

Buy a copper pipe and a pump (or you can use your pool’s pump). Run the copper pipe over a fire pit and attach one end to a garden hose. Attach that garden hose to a pump to pull water from your pool.

At the other side of the pipe, attach another garden hose leading back to the pool. Now start a large fire to heat up the copper pipe, and start the pump.

Now, cold water will be pumped out of your pool, through the hot copper pipe where it will get heated up, and back to your pool as warm water.

This solution requires a bit of setup, but once that’s done, then you have an easily reusable DIY pool heater that requires just a bit of firewood as an energy source.