Is Your Fiberglass Pool Leaking?

By Shurby

Swimming pools are associated with relaxation, fun and recreation – part of the good life that comes with living in Central Florida! If you’re a homeowner who has a fiberglass pool, you get a little more of all three, as these pools require less maintenance as compared to vinyl liner and concrete pools. However, low maintenance doesn’t mean no maintenance. It’s essential to regularly maintain and check for leaks in your fiberglass pool to get the longest life and most enjoyment out of it.

What is a Fiberglass Pool?

If you bought a house with an existing fiberglass swimming pool, a little background information might be in order. This is a one-piece pool manufactured in a quality controlled facility. The pool is constructed by a multi-step process using a variety of durable materials – including, of course, fiberglass, which is a combination of resin and glass fibers that creates a fiber-reinforced plastic. To create a smooth finish, a weather-resistant gel is added to the fiberglass mold. 

Because a fiberglass pool is delivered in a single piece, it’s relatively easy and fast to install. One perceived disadvantage is that shapes and sizes are limited. Today’s manufacturers, however, offer a wider range of designs, which give the pool a more custom appearance.

In addition to ease of installation, another advantage to a fiberglass pool is its smooth surface, which makes cleaning much less labor-intensive than a concrete pool. Also, the smooth-yet-tough surface is more durable than the vinyl of a vinyl liner pool, which can tear. With the right maintenance, you will save money in the long run – having more to spend on grilling, parties and entertaining by the pool!

Where Leaks Can Occur in a Fiberglass Pool and What to Look For

Leaks in fiberglass swimming pools can be grouped into two categories:

  • Cracks in the pipes and fittings in the system.
  • Cracks in the fiberglass shell.

Identifying cracks in the pipes and fittings – In such locations, the pool system’s suction or return pipes are the most likely culprit for leaks. A leak detection expert can determine the precise rate at which the pool water is being lost. If you want to troubleshoot for yourself, perform the bucket test – also called the evaporation test. Our website has easy, step-by-step instructions for this simple, yet effective, diagnostic method.

If the bucket test indicates your pool is losing water at a higher rate than evaporation accounts for, the next step is to investigate the plumbing and the equipment pad. Start by testing if the pump is having problems getting primed, since that can signal a suction-side leak, either underground or at the pump.

If the usual checks don’t seem to isolate the issue, it could be time to call us. Our experienced techs will test for leaks with cutting-edge techniques, and can locate even well-concealed cracks. The inspection may include disconnecting all equipment and plugging off the ends of the pipes to pressurize all parts of the plumbing system, then running the pool water through the closed circuit. If a pressure loss is detected on any of these systems, ultrasonic detection equipment may be used to find the exact location of the leak.

Identifying cracks in the fiberglass shell – If the leak is not in the plumbing pad or equipment, it’s time to check for leaks in the pool shell. It is common for fiberglass swimming pools to leak wherever there is an opening in the shell. So if there is any penetration in your pool – such as a light fitting, a return outlet, a main drain outlet, or a skimmer throat, there can be a potential for leakage. Moreover, check around the shell base where the pool walls start to curve upwards.

Cracks in the shell are usually caused by ground movement, uplift, or roots. However, as fiberglass shells start to age, they may develop cosmetic fatigue cracks that detract from the pool’s appearance, but don’t leak.

To identify the source of your underwater pool leak, you can start by injecting dye into the swimming pool near the suspect spots. You can use methyl red dye – which is used for pH testing – or any red food color. To perform this test, place a syringe filled with red color near the suspected leak area underwater, slowly injecting the color and then checking for leaks. If repeated dye testing fails to give you results, then try another technique that will help you identify the crack’s location. Turn off the pump and plug off the pipes. Now let the water level of the pool drop and check where it stabilizes. It will stabilize below the leak level, allowing you to narrow down the location of the leak.

Fiberglass Pool Maintenance 101

As mentioned earlier, maintaining a fiberglass pool is much easier than a concrete pool. The gel surface coat of a fiberglass swimming pool is nonporous and smooth, leaving little to no room for the growth of algae. This saves you from brushing and other rigorous cleaning work typically required for its concrete counterpart. However, if algae still manages to enter your pool, River Pools provides step-by-step instructions for eliminating it in 24 hours by using the SLAM (Shock, Level, And Maintain) method to shock the pool.

Cleaning products for a fiberglass swimming pool – With a concrete pool, you need to go for acid washing and steel brushing when it comes to cleaning your pool – but for fiberglass pools, the scenario is quite different. Writing for River Pools, fiberglass pool expert Holly Jender recommends the following approach:

“Fiberglass pools require a gentler touch in terms of cleaning products and tools. Harsh cleaners can damage the gelcoat and even change the water chemistry. Use a damp rag and a simple pool cleaner to remove dirt and grime without damaging your pool.”

Check your pool water chemistry – All pools must have proper levels of the following:

  • pH
  • Total alkalinity
  • Free chlorine
  • Cyanuric acid
  • Calcium hardness

Fiberglass swimming pools usually need less adjustment, as their surface is inert, which doesn’t affect the water chemistry.

Run your pool filter – We all know that all swimming pools require a filter system. But how long do you need to run it? Fiberglass swimming pools require only one circulation per day to keep the pool’s water clear and clean. This will save you electrical energy and money.

You can also use the following formula to calculate the time for which you need to run your pool filter:

Hours to run the pool filter = pool volume ÷ filtration rate

The Take-Home Message

With regular maintenance and checking for early signs of pool leaks, your fiberglass pool will ensure that your summer is all about carefree fun for many years to come!

Certified Leak Detection has more than 30 years of experience in leak detection and repair for swimming pools, spas and hot tubs, as well as slabs and foundations. Serving areas throughout Central Florida – including Orlando, Longwood, Lake Mary, Sanford, Kissimmee, Clermont and Winter Springs – our team is ready to answer your call.

Contact us for quick, reliable service.