Things You'll Need
Red food dye
Pool repair putty epoxy stick
When there is a leak, the level of the water can help determine where the leak is located. If the level stops at the skimmer box, that is the first place to check. If it stops below the return fitting, then the leak is probably in that area.
An in-ground pool requires regular maintenance and upkeep. For example, it may become noticeable at times that the pool's water level has dropped. On hot sunny days, the culprit is usually evaporation, and is no cause for concern -- it can be remedied by simply adding water. But if the water level drops an inch or more per day during rainy weather, there may be a pool skimmer box leak. This is a weak area of the pool and probably the most common source of leaks.
With the pool pump off, remove the cover to the pool skimmer box. The pool water level must be above the area where the skimmer box meets the pool wall. If it is not, add water to the pool until it is at least 1 inch above this seam.
Add a few drops of red food coloring into the water at the skimmer box and watch to see if the water is flowing. If you see red dye flowing through the pool wall at the seam, you have located the leak.
Apply some pool repair putty/epoxy stick adhesive sealant to the affected area. Remove a piece of the putty from the tube and knead it with your fingers until it becomes pliable. Bring the kneaded putty under water to where the leak is located. Press the putty into place with your fingers, then rub it smooth. The putty will cure to white within 30 minutes.
Check for other leaks If the water level continues to drop after using the adhesive. Other common sources of leaks are the areas around the vacuum and return fittings.
Based in Florida, Rosemary Rugnetta has been a freelance writer since 2007 specializing in home and garden topics and real estate/mortgage. She is a former property manager and mortgage underwriter who writes for eHow and Answerbag as well as private clients. She has completed continuing education courses in writing, construction management and design.