Hot tubs provide a great source of relaxation and entertainment for homeowners. However, maintaining the proper function of your hot tub is crucial to ensure that your spa experience is enjoyable and safe. One important aspect of maintaining your hot tub is understanding and taking care of the pumps and circulation system. In this blog, we will discuss the different types of hot tub pumps, the importance of proper sizing, maintenance and troubleshooting, energy efficiency, and circulation pumps.

What are the Duties of Hot Tub Pumps?

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By now you have done your research and you know that there is a lot of marketing around pump sizes and purposes. We are going to make it simple and explain the basics of the duties of the pumps, types of pumps, and important things to look for. There are two main duties for the pumps in a hot tub.

Water Circulation

The first duty of a hot tub pump is to circulate the water. Water must be circulated through the filters and heater regularly to keep your water warm and filtered. Frequently moving water makes it much harder for dirt, debris, and contaminants to take over the water vs when it is still. That is why keeping your hot tub on and using it frequently will actually make the water easier to maintain. 

Power the Jets

The second main function of a pump is to power the jets. This can be accomplished in a variety of ways. Some tubs have pumps that are dedicated to powering the jets. Others have pumps that can operate at high and low speeds and are able to both circulate the water as well as power the jets.

If you want to learn more about jets, take a look at our In-Depth Guide to Hot Tub Jets

Types of Hot Tub Pumps

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Hot tub pumps are responsible for circulating water through the spa’s filtration system, heating system, and jet system. They come in three main types: single-speed, two-speed, and variable-speed pumps.

Single-speed Pumps

Single-speed pumps are the most basic type of hot tub pump. They operate at a fixed speed and are the most affordable option. They can be used to power the jets, circulate water through the filtration system, and help to heat the water. These pumps are easy to maintain and can be less expensive to purchase, however there are some drawbacks. Single-speed pumps are the least efficient style of pump, but do work well with a dedicated circulation pump.

Two-speed Pumps

A Two-Speed pump is a variation of the single speed pump, in that they both use what’s known as an induction style motor. The difference is that a two-speed pump has a low speed option, which is far more versatile and efficient than running the pump on high speed all the time. This will also allow you to potentially run your hot tub using a single pump.

Variable-speed pumps

Variable-speed pumps can operate at different speeds, which makes them the most energy-efficient option. Instead of using induction motors like other single and two-speed pumps, they come with a permanent magnet motor, just like the ones in electric cars. This means you can dial in the exact flow rate you need, following the golden rule of pool circulation: slower is better. By slowing down the water flow, you’ll experience less friction and greater efficiency for your entire system. Not only that, but these pumps are also much quieter, vibrate less, run cooler, last longer, and often come with digital control and advanced diagnostics.

Circulation Pumps

Circulation pumps often refer to a pump that is dedicated to circulating the water through the heater and the filtration system. These pumps operate at a much lower speed, are ideal for efficiency, and don’t overpower the circulation lines. The jets can also be run on a separate water circuit.

Proper Pump Sizing

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The ideal pump size all depends on the particular hot tub you have and what your priorities are. Whether you are looking for a tub that is energy efficient or are looking for the best hydrotherapy massage, there are some good rules to go by.

Energy Efficiency

If you are looking for a hot tub pump that is energy efficient, a variable speed pump is usually the best way to go. That being said, there are potentially different set ups that may work better for a particular hot tub. That is why you should always look at the volts and amperage of the specific pump or collection of pumps you are interested in. This will allow you to calculate the exact amount of energy they will use.

Hydrotherapy – A Bigger Pump or More Jets?

Neither. A common misconception is that more jets or bigger pump result in a better hydrotherapy experience. The truth is the two main factors you need to consider when it comes to hydrotherapy are the types of jets and hp-to-jet ratio. In a previous article, we went into full detail explaining the different types of jets, and now we are going to look at the power behind them. 

HP to Jet Ratio

The strength of a massage in a hydrotherapy system is not determined by the size of the pump, but by the size of the jets. A larger jet nozzle results in a higher GPM rating. The size of the pump is determined by adding up the total nozzle area of all the jets it is expected to power. As a general guideline, large jets with a GPM of 15-20 require 1/4 horsepower per jet. As many as 8-10 small jets can be powered by a single horsepower. 

Getting a larger pump than what the jets require doesn’t increase the power of the massage. It only makes the tub more inefficient leading to wasted energy. 


In conclusion, hot tub pumps and circulation are essential components of a spa experience. They provide the power to maintain clean water, ensure accurate temperature control, and improve hydrotherapy benefits. It’s important to invest in high-quality pumps. If you’re ever unsure about what type of pump is right for your particular needs or budget, don’t hesitate to consult with the experienced professionals at Great Bay Spa & Sauna who can help guide you through the process.