Leaks and Water Loss

It is not uncommon to have water loss in a pool and/or spa for a variety of reasons. Often times, that water loss is due to simple evaporation and even varies according to humidity and air temperature. 2" per week is a very realistic amount that pool water can evaporate. Additional water loss can also occur if the pool has spa spillways, waterfalls, or other water features.

To determine if evaporation is the culprit to your pool's water loss, it is recommended that a bucket test be performed:


To do a bucket test, you should first turn off all auto fill systems and water features. Place a 5 gallon bucket on the 2nd step in the pool. Fill the bucket with pool water to the exact same level as the pool. Wait three to five days and compare the water level in the bucket to that in the pool. If the water levels are the same, then the water loss in your pool is due to evaporation. If the water level in the pool is below that in the bucket, a leak or leaks may exist.

Types of leaks
Determining you have a leak does not always mean there is a crack in the structure. Leaks can come from a variety of different places. The following are places you should examine:

Check Valves
90% of the time, a leaking spa is due to a broken seal in the check valve. A check valve is unit that stops the water from going from the spa back into the pool.

There are tale-tale signs of a cracked or old check valve. These are a few of the signs:
Spa water is dropping when the equipment is off
Spa water is only dropping down to the water level of the pool water
The pool water is rising as the spa level drops

Reasons for a bad check valve:
Dog hair
Dirt (does not have to be large dirt particles)
It's old and just needs to be replaced
Hinges are not completely shutting the valve

How to clean/replace a check valve:

Find the right one. There may be multiple check valves on your pool.

Unscrew each screw on the cap

Take the lid off and pull out the check valve seal


Run your finger or a clean/wet rag over the seal

Replace the seal and tighten all screws. Make sure you put it in the same way it came out.


If the check valve is clean with good rubber, and you are still experiencing problems, call a pool professional. They will usually be able to target the problem to the right place and help you to find the solution.

Skimmer Cracks

A cracked skimmer is usually caused because there is significant ground movement which dislodges the skimmer from the pool structure. You should be able to see this type of crack by looking into your skimmer. You should consult a professional to repair this type of crack.

Seepage through a light, jet, or other fixture in the pool.
Sometimes, water can penetrate though small separation points of the structure and the fittings of the pool. An easy way to test weather there is a separation is to use the red dye that is commonly used for pool chemical testing and squeeze it closely around each fitting. If the red dye gets sucked into the fitting or structure, then you a found an area where seepage is taking place. Consult a professional to repair this type of separation.

Structural Crack
Structural cracks can be caused by a variety of conditions. Often times you will find them in the corners of benches, on the waterline tile, or in the transition areas of wall to the floor of the pool. If there are visual cracks, you should consult a professional.

Plumbing Crack
Sometimes movement in the soil will cause pipe joints to come apart or even break. The only way to test for this to pressurize the entire plumbing system and see if it holds that pressure. Once it is determined that it does not hold pressure, special equipment is used to locate where the leak is so it can be repaired.