You designed your dream backyard. The pool, the landscaping, the patio. So much effort, and so worth it. It’s a beautiful thing.

Except you didn’t design the aggressive Air Bubbles shooting out of the returns on the pool walls. So what’s up with that?

Why are you getting air bubbles in your swimming pool?

This is a common problem, especially when you’re first opening your pool for the season.

A few bubbles in the pool or the pump is normal, but noisy churning and lots of bubbles indicate that you have a problem.

Quick recap!

Your pump/filter system works like this.

Your pump pulls the pool water from the skimmer(s) on the pool wall and the main drain(s) on the pool floor.

This water hits the first part of the pump, a small sorta filter called the strainer pot. It catches any major debris right away.

After the water goes through the strainer pot, an impeller (spiny thing!) in the pump pushes it on to the filter.

Whether you have a sand, cartridge, or D.E. filter, the water goes through it to remove dirt, debris, and (if the filter is good) bacteria.

After the water is filtered, it flows through the plumbing to the heater/chiller (if you have one) and then the salt chlorine generator (if you have one).

The clean water returns to the pool through the aptly named return jets on the pool walls.

Okay, so how does that translate to this issue?

Air bubbles in your pool mean that air is being sucked into the line on the suction side of the pump.

When you first open your pool, you’re putting a lot of things back together in the filter system. Nine times out of ten, the issue isn’t in the underground plumbing, but in your above ground equipment.

(And above ground issues are often easier to fix because you don’t have to dig anything up! Yay!)

What are the most common reasons for pool air bubbles?

Air bubbles in your pool mean that air is being sucked into the line on the suction side of the pump. It’s likely happening because of one of these issues:

• The pool water level is too low
• The strainer pot lid isn’t on tight or its O-ring is loose/absent/compromised
• The union between the valves and the pump isn’t tight or its O-ring is loose/absent/compromised

1. Is your water level correct?

First, check how high the water is—specifically, in relation to the skimmers.

If the water level is too low, the skimmer will suck in air and send it to the pump/filter system.

What’s the proper water level for a swimming pool?

We recommend you keep the water halfway to three-quarters up the skimmer.

2. Is your strainer lid on tight?

Second, check the strainer pot lid.

It should be closed tight. If it’s not snug, you’ll suck air through that lid into the pump.

Check the O-ring under the lid:

1. Turn the pool pump off.
2. Take the lid off.
3. Check the O-ring is there and in good condition.
4. Make sure the O-ring is seated.
5. Make sure there’s no grit or debris that might be obstructing the lid from getting a secure close.

3. Is your pump/valve union on tight?

Third, check the union (fitting) between the pool pump and the valves.

Now, this little friend is the most common culprit.

It’s where we take our plumbing apart, so it has a pretty high chance for missteps.

Remember the O-ring from the strainer pot lid? Surprise: there’s an O-ring here too!

Check the O-ring at this union:

1. Turn the pool pump off.
2. Remove the nut over the union.
3. Check the O-ring is there and in good condition.
4. Make sure the O-ring is seated in its groove inside the union.
5. Make sure there’s no grit or debris preventing the union from closing tightly.

 

Many times, when you’re putting the pump/filter system back together, the union’s O-ring will slip out or fall out of its groove. And when you throw it off its groove, bad things happen—like letting air in.

Reminder: When you tighten your union back up, make sure that the flange (ridge) is flush with the back of the nut. If it’s not, something is obstructing the union from fully closing.

Still have air bubbles in your pool?

If you check all 3 of these things and still have air bubbles, you might have a bigger problem—like a suction-side leak in your plumbing, which would be coming from either your main drain or your skimmer line.