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Swimming Pool Return Jets And Water Circulation (Explained)

A swimming pool is the sum of its parts, and they all need to work together to ensure efficiency and high performance.

Keeping the water clean is more than just the addition of the proper chemicals.

Pool return jets play a bigger role than most might think, contributing not only to the state of the water, but the health of the pool structure as well.

What Are Pool Return Jets?

Pool return jets (sometimes referred to as eyeballs) are those fun little things you’ll find on pool walls that shoot powerful streams of water into the pool. Many swimmers stand against them for a relaxing massage.

But return jets actually have a much more functional purpose. They’re called return jets because of how the chain of circulation works in a pool.

Dirty water gets sucked out of the pool via the skimmers and main drains, it then goes through the pool filter system, before being “returned” to the swimming pool by the jets.

Most pools will use a minimum of 2 or 3 return jets, and install them in the deep end, shallow end, and any other area of the pool that provides balanced circulation to the water.

Additionally, if the pool is designed with a swim out, step jets are usually installed on either side, to keep the water circulating around them.

Why Do You Need Them?

We already touched on the fact that return jets are necessary for pool water circulation, but there are a few side benefits that are worth mentioning.

They Push Out Filtered Water

In order for your pool to be swimmable, it needs to stay clean. This is done through the addition of sanitizers like chlorine.

Unfortunately, chlorine can only do so much, and over time it becomes less effective. For this reason, pool water requires constant “topping up” of the water’s sanitizing chemicals, and is also put through a filter. 

After the dirty pool water is sent through the filter, it gets cleaned of any debris before being pumped back into the pool via the return jets.

They Distribute Your Pool Chemicals

Chlorine isn’t the only chemical that makes up balanced pool water, and for the most part, you’ll be forever adding things to the water to keep it from going haywire.

Conversely, if the water has already gone sideways, you’ll have to add things to it to bring it back into harmony.

Water on its own is still. Adding chemicals to the pool is all well and good, but unless you have a gigantic stir stick, those chemicals have to be circulated somehow. 

This is where the return jets shine, keeping the pool water constantly circulating and mixing up the chemicals so you can swim without getting sick.

They Prevent Buildup On Surfaces

When the water is well-circulated, it makes sure there are no dead spots in the pool. 

Dead spots are easily identifiable by the collection of fine dirt, presence of algae, and buildup of calcium deposits along the waterline.

Notorious dead spots the pool’s entry areas, whether it be a ladder or swim out. Some pools aim a jet(s) specifically at the entry spots so that there are no issues with surface buildup.

How To Improve Circulation With Pool Jets

Circulating the water efficiently is crucial to keeping it healthy. Here are some tips on getting the best performance from your pool jets.

Ensure They’re Actually Working

The easiest way to make sure your jets are fully operational is to place your hand over them and feel how much water is being injected into the pool. If the stream feels weak, there is probably an issue somewhere in the filtration chain that needs to be fixed. 

An air leak can affect the return jet pressure. If you notice air bubbles around the jets, that’s a telltale sign you have a leak. This can come from a low water level (pool water should always be halfway up the skimmer height), or from wear and tear on various parts of the filtration system (ie. defective gaskets or o-ring, joint issues in plumbing). 

Additionally, your pool filter pressure gauge should be checked. If the pressure is low compared to your baseline PSI, it’s usually a good indication that you’ll have to do some snooping to find out what’s causing the low water flow.

Install Enough Of Them

For most pools, 2 or 3 return jets will do the job, but for larger pools, you’ll have to install more to keep the water fully circulated and the pool properly filtered.

Placement of the jets will also be important as you don’t want to have them grouped together. This will lead to inefficient water circulation, and that will be the quickest way to start having problems with your pool water.

Choose The Correct Size

You may have noticed that some pools don’t have the same size return jets installed on them.

In fact, it’s more beneficial to use jets of different size eyeballs around the pool, due to the nature of water circulation. 

Water is inherently looking for the path of least resistance, in this case, the quickest way to get to the pool skimmer. For this reason, jets that are far away from the skimmer need to shoot a stronger current of water compared to those that are installed close to the skimmer.

Eyeballs sizes you’ll find are ⅜”, ½”, and ¾”. For far away placement, you’ll want to go with a smaller size, as this will create more back-pressure than mid or large-sized eyeballs.

Angle Your Pool Jets Efficiently

Jets can angle water flow however you wish. But to be most efficient, they should be angled down at 45 degrees.

Aiming the jets to the bottom of the pool has a few advantages. There’s less heat loss, less evaporation, and less burn off of the chemicals in the new water. Also, as the water is shot into the deep sections of the pool, there’s more water turnover – meaning it’s helping cycle the pool water more efficiently.

If you aim the jets straight, or up toward the surface, the effects on the pool water will be the opposite – more heat loss, evaporation and burn off, and less efficiency in the turnover of the water.

Don’t Rely Only On Your Jets

The jets will do a lot of the circulation work, but you have to make sure other areas are fully operational as well.

Things like your pool pump, pump basket, filter, skimmer, and skimmer basket all play a role in keeping the water cycling properly. 

You’ll also want to ensure that the water has the proper pool chemistry levels in it. If chemicals are out of balance it can affect the circulation, as issues like calcium scale can result in clogs, and acidic pools can corrode the filtration system.

Just Go With The Flow

Of the many parts that go into a pool, pool return jets are an important and multi-functional feature.

By properly injecting and circulating clean water into the pool, you’ll keep it safe for swimmers, and help to avoid any issues with buildup on surfaces.

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