How to install an extra return jet in an above ground pool

Above ground swimming pools are nice economical alternatives to in-ground pools. They are very basic though in their set-up. One of the super basic things is how the pump and filter attach to the pool.

Above ground pools only have two openings – the skimmer to draw in unfiltered water and the return jet to send filtered water back. That’s it.

Just having one inlet going to the pump and one outlet coming from the filter is not ideal when it comes to circulating filtered water in a swimming pool. Some will want to improve this set-up by adding an extra return jet.

QUICK STEPS

1 Purchase a standard above-ground return fitting 2 Purchase a 2 5/8″ or 2 1/2″ hole saw
3 Find out how far down your existing return jet is from the top of the pool’s wall
4 Go away from and parallel to the existing return jet at least 18”, make a center mark the same distance down from the top of the wall as the existing jet.
5 Drill in the marked center point with the guiding drill bit, then drill the hole using the hole saw.
6 Use a round file or a large screwdriver to smooth out the edges of the new hole
7 Replace the liner and install the new jet in the new hole
8 Plumb the new jet line to the existing jet line using a “tee” fitting.

WHY ADD AN EXTRA RETURN LINE TO AN ABOVE GROUND POOL?

Some with a very basic understanding of how a swimming pool works will want to improve their above ground’s performance by adding an extra return line.

This isn’t a bad idea at all. Adding a second return line to a pool will improve its circulation and potentially will increase the water flow a little. Unfortunately, adding a second return line to an above-ground pool to improve its performance may be better in theory than in reality.

WHAT ADDING AN EXTRA RETURN JET DOES IN THEORY

First off, adding an additional return jet/line to your above-ground pool will accomplish two things in theory – it will increase water volume coming back to the pool from the filter and it will improve circulation in the pool.

1 How it increases water volume – By adding an extra return line, there is another place for the water coming from the equipment(pump/filter) to go.
So, if there is any restriction of flow coming from the filter, then the extra line should stop that, thus improving water volume returning back to the pool.

2 How it increases circulation in the pool – By adding an extra return line, you are sending filtered water to the pool in a different area. This will allow the filtered water to disperse faster and better in the pool, which means it will circulate better.

WHAT ADDING AN EXTRA RETURN JET DOES IN REALITY

In this current world that we live in, it’s important to know the difference between theory (aka the internet) and reality (outside where there is a hot round ball in the sky). Here then is the reality of the situation.

1 How it may NOT increase water volume – Have you ever heard of the term “bottleneck”? This means that there is a restriction where there is a reduction of space. In this case, there are restrictions of water flow or “bottlenecks” within the path of water coming from the skimmer (unfiltered) and returning to the pool(filtered).

The openings for the pump and filter are usually for 1.5” pipelines. And the openings at the bottom of the skimmer and the return are for 1.5” too.

This means that even if you increase the pipe size to maybe 2”, there will still be 1.5″ restrictions on those six places in the system. The six places being the skimmer, inlet and outlet of the pump, inlet and outlet of the filter, and the return jet.

So, even if you elect to make all the piping 2” big, the flow will still be restricted when flowing through these six areas.

This same hydrodynamic logic applies when adding an extra return line. The water pressure may ease a little after the filter with an added return, but the restriction is about the same as there are still those 1.5” openings(restrictions) everywhere.

In reality, an extra return jet WILL INCREASE FLOW some. This is because the smallest bottleneck in the whole system of an above-ground pool is at the directional fitting in the return jet. So, by adding another return, you will then have two openings that will ease this restriction.

This isn’t a big increase and probably isn’t worth adding a whole extra return line just for that. A much easier fix to that is to remove the eyelet from the existing return.

2 How it may NOT increase circulation in the pool – By far, the majority of extra return lines in above-ground pools are installed within two feet of the existing one. This is because it is much easier to plumb-in the extra line when it’s closer to the original return fitting.

If a second return line is added close to the existing line, then there won’t be much difference in the circulation of the pool.

Now, some will install the additional return jet/line on the opposite side of the pool. Doing this will greatly improve the pool’s circulation. This is because freshly filtered water will be entering the pool much farther away from the existing return jet. This mixes in the filtered water well and quicker in the pool.

Adding a return line further away from the existing return line is a much bigger plumb job. With this, the plumbing will have to go from the new return jet down and buried. That line will then have to connect with the existing return line in the ground, preferably about half the distance between the two. This means a lot of PVC piping and a lot of digging.

ADDING AN EXTRA RETURN JET

If you have determined that you want to add a return line, then here’s what you need.

MATERIALS NEEDED:

Standard above-ground pool return fitting
2 5/8”or 2 1/2″ hole saw
Tape measure
Marker
Round file or sandpaper
Large adjustable wrench
100% silicone
Utility knife
1.5” PVC fittings and pipe
Hack saw
PVC glue

Making the new hole in the wall

This is a big part of adding a new return line and you don’t want to get it wrong.

NOTE: If you are adding a new line to an above-ground full of water, then you will have to drain the pool down to about half-way and remove some of the top rails, top connectors, and stabilizer bars above the area where you want to make the hole. Then you’ll peel back the liner far enough away from the area you want to make the hole. A new hole will be made in the liner later.

1 Locate the drill point – From the inside of the pool, use the tape measure to find the distance from the top of the wall down to the middle of the existing return fitting/hole.

Locate the area that you want the new return and measure down the same distance as the existing return and make a center mark using a sharpie or pen.

2 Drill the guide hole – You’ll be drilling a big hole, but first you have to drill a small hole directly in the middle of where the big hole is going. Don’t worry. This is easy as there’s a drill bit attached to the center of the hole saw.

From the inside of the pool, line the center drill bit up with the mark you made on the wall and drill the hole. You are now set to drill the big hole.

3 Drill the hole – With the center guide bit in through the wall, start to drill the hole. You will be pressing against the wall in different areas with the saw as it cuts the wall. Try to allow the saw to cut the hole evenly.

Once the hole is completely cut, remove the saw and be careful with the perfect circle of wall that was cut out. It will be very sharp (like a Ninja star).

4 Prepare the hole edges for the return fitting – the edges of your new hole will be very sharp. You’ll want to dull this sharpness up before installing the return jet.

Take a round file or sandpaper and smooth out the edges of the circle. Be careful with this. This hole edge can be razor-sharp and will easily cut you wide open.

File and/or sand the edges until dull to the touch. The hole is now ready for the fitting to be installed.

NOTE: If you want, spray the edges of the new hole with a paint or rust inhibitor. Spray from the inside of the pool out. That way you won’t get any paint on the outside finish of the pool wall.

Installing the new return fitting

At this point, you should have two identical round holes in your pool wall. The new hole should be exactly the same distance down from the top as the existing one.

You can now either replace the liner (if the pool already had water in it) or install the new liner like normal.

For a DIYer, I recommend waiting until the pool is half full before installing the return fitting and skimmer. When you are ready, install the new return fitting exactly the same as you would your existing one. The holes should be exact.

Plumbing in the new return line – As mentioned earlier, most added return lines are within two feet of the existing line. This makes plumbing it in much easier.

To help keeps things simple, understand that filtered water (coming from the filter) will be coming out of the filter in one line. Now that you have added a second return fitting, that one line will at some point have to split into two lines going back to the pool.

Going from one line to two lines means that you will need a “tee” fitting. A “tee” fitting has three openings. One opening will connect to the filter line, and the other two will connect to each return line (the existing return and the new one).

So, at some point, you’ll be adding a “tee” fitting to the filter line going back to the pool.

If your new return line is close enough to the existing one, then you’ll connect the two lines high up off the ground and parallel with the return jets. Most use PVC hard piping for this and it’s fairly simple plumb job.

PLUMBING A RETURN LINE FURTHER AWAY FROM THE EXISTING ONE

It’s nice to add a new return line far away from the existing one, but you will have to do some extra plumbing.

When the returns are close, they can be attached or plumbed together above the ground. When you have a return line all the way on the other side of the pool, then it’s best to dig a trench over to where the equipment is (and the existing return line) and attach it underground.

When doing this, start with the new return fitting and come straight out glueing in at least a five-inch piece of PVC away from the outside of the pool.

Now, use a 90° fitting and PVC pipe down into the ground. From there, you can dig a trench to hold the pipe along the outside of the pool all the way around until you get just underneath the existing return line.

From there, use a 90° fitting to come back up out of the ground and attach the existing return line in PVC using a “Tee” fitting. Read above.

Note: The easiest way to run the new PVC line from the return line on the far side of the pool would be to come straight across the pool and bury the pipe under the pool.

Personally, I avoid burying any piping directly under the pool if I can. In this case, I usually run and bury the piping around the outside of the pool.

SOME BASIC HYDRODYNAMICS. VERY BASIC

It’s important to note that if you add in an extra line in the easy way that I described above, then you won’t get as much flow coming back to the pool from the farther (new)return jet.

This is because of the placement of the “tee” fitting, which is where the flow goes from only one line to two(for each return jet). With the “TEE” being so close to the existing return and so far from the new return, then the pressure to the closer return fitting will be much greater.

This may not be a big deal for most as there still will be plenty of filtered water returning into the pool from the far jet. Some will not be happy with this (although they probably should be), so they will have to do more plumbing.

To get the two jets to have equal pressure, you will have to install the “TEE” fitting about half the distance between the two returns. This means that if the new return is on the opposite side of the pool, then the “TEE” (split fitting) will have to be plumbed in about one-quarter of the way around the pool.

By doing this, you will now have an equal distance between the return jets and where they split off or come together(depending on how you want to look at it).

Confused? Me too. Yeah, just plumb in the new line in the easiest way you can and be done with it.

WANT BETTER CIRCULATION FOR YOUR ABOVE GROUND POOL? CONSIDER ADDING A MAIN DRAIN INSTEAD

If I were to decide whether a pool should get an extra return line or a main drain, I almost always recommend a main drain over even two extra return lines. So, before you decide on adding an extra return line, read about main drains and above-ground pools here.