How to Find and Fix a Pool Leak

Pool leaks can occur anywhere in or outside your pool. Before searching for the leak in your pool, make sure you check your entire filter system area, including the pump, filter, heater, chlorinator, etc.

If you have an inground pool, leaks can also occur by cracked piping underground. If you suspect this, call a local pool professional to pressure test the lines for possible cracks.

How to Find and Fix a Pool Leak

Before you start searching for the leak, you must determine that you have a leak and not losing water from water evaporation. If you’ve already done this process, you can skip ahead.

How to Determine if you Have a Leak (The Bucket Method)

What You’ll Need:

1. Fill and Mark The Bucket
Fill a plastic bucket with about 3/4 full of water. Mark where the water line is on the inside of the bucket with a Sharpie marker or strong tape.

2. Place In The Pool
Float the bucket in the pool (shallow end for ingrounds) and mark the water line on the outside of the bucket with a marker or tape. Let it float for about two or three days.

3. Time to Check The Results
If the water inside and outside the bucket has gone down the same amount, your pool is losing water due to evaporation. However, if the water level has gone down more outside the bucket than inside the bucket, your pool has a leak.

To find the leak yourself without hiring a company, here’s how:

How to Find a Pool Leak (Ink Method)

What You’ll Need:

1. Let The Pool Drain
Start off by letting the pool drain. This is tricky because if the leak is at the bottom, then it will drain all the way – we are trying to avoid that. However, if you think it’s coming from the top of the wall, then let it drain.

When the pool stops draining, then you will know it’s somewhere along the wall where it stops.

2. Check The Ground and Walls Around The Pool For Wetness
This will help determine the area of the leak. Now you know the height of the leak, because it’s where the water stopped draining, and now you know the area because the ground or pool wall will be wet.

Keep narrowing down before using the dye to find the leak. Once you’ve got an idea where the leak could be, jump in the pool and find the exact location with the dye.

3. Use Food Coloring (Or Dye) To Pinpoint The Leak
Go to the area where you think the leak might be. Move slowly and try not to disturb the water.

Squirt the dye in the water close to the wall. If the leak is near, you will see the dye move towards the leak source like a current. If you suspect your leak is at the bottom of your pool, put on those goggles and do the same thing. The reason you don’t want to disturb the water is because you don’t want the dye running wild.

How to Fix a Pool Leak

If you own an inground pool made of concrete, plaster, or fiberglass, you have the option of doing it yourself, but I recommend that you call the company that originally put in the pool or a company to come out and patch it professionally.

If you would like to attempt the repair yourself, here is a guide.

How To Patch A Leak In Your Pool (Vinyl Liner)

The smaller your pool, the easier it is to find a leak. But just because you have a leak, doesn’t mean you have to replace the liner. There are vinyl liner patch kits that work underwater.

Hydro Tools 8815 4-Ounce Vinyl Pool Linear Repair Kit
List Price: $14.99
Price: $10.04
You Save: $4.95 (33%)

Works underwater on vinyl liners and inflatable pool toys.

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[WARNING: Do not entirely drain a vinyl liner pool. Once the vinyl touches air it will start to shrivel up and become brittle. This will cause a problem when you go to refill your pool – it could cause tears and rips in your liner.]

Your vinyl patch kit comes with a big sheet of clear or blue vinyl. Cut out the patch in a big circle – not a square – and make it larger than the leak hole. Circular patches don’t have corners which are easier to pull up when using the pool.

Cover the entire back of the patch with glue that comes with the kit. If you are not under water, apply the patch over the leak hole and apply pressure for 2 minutes.

If you leak is under water, fold the patch in half so that the glue will come in little contact with water. Go to where the leak hole is, and it one motion, open it up while applying it to the leak hole underwater. Apply pressure to the patch for 5 minutes. If the patch does come off over time you can always re-patch it.

Happy Swimming!

How to Find and Fix a Pool Leak

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  • Michelle Davis

    It looks as if water is leaking from the pump. The pipe that drains as I backwash is dripping as filtering pool. I have not noticed this before and my water level is lowering in my inground pool with a sand filter. Any ideas of what to do? Also, why does my multi-valve have a whirlpool option? It isn’t leaking as much in this setting rather than filter, but unsure about whirlpool setting.

  • Matt Giovanisci

    If it’s leaking from the pump, it could be a bad seal. Easy to replace.

    For the multiport valve, you need to replace the spider gasket inside. Easy also.

  • Becca Dodge

    What I need is a way to temporarily slow my leak. I have the underwater repair kit on its way. There are no places around me that have it in stock. I just need to slow it down for a few days, any ideas?

  • Matt Giovanisci

    Any vinyl patch will work. You can find them at Home Depot and Target and Wal-Mart

  • Becca Dodge

    It’s low in the pool so I need an underwater one. Hence the ordering of a kit. I put a regular vinyl patch on the outside to try and help, to no avail. Also tried duct tape, hahahaha.

  • Toni DeGryse Lorenzen

    Water level has dropped below the light. Appears to have finally stopped leaking so we check all around the walls but could not find a tear. We also did the die test and nothing. Now what?

  • Matt Giovanisci

    Replace the light?

  • aaron

    So Matt, you indicated that I should let the pool drain to determine the location of the leak. If it drops below the skimmer, I have to shut off the skimmer intake to avoid air getting into the lines, correct?