Osmosis In Fibreglass Pools: What Is It & Can I Still Swim In It?
Osmosis in fiberglass pools occurs when water from the surrounding environment (such as groundwater or floodwater) moves into the fiberglass pool through the gel coat or the surface layer. This happens due to a difference in water pressure, where water flows from an area of lower solute concentration (the pool’s surface) to an area of higher solute concentration (the pool water or the interior layers of the fiberglass).
How Osmosis Affects Fiberglass Pools
Blistering or Bubbling:
Osmosis can cause water to be absorbed into the fiberglass shell, which may lead to the formation of blisters or bubbles under the pool's surface. This is particularly problematic if the pool’s gel coat is compromised, damaged, or aging.
The absorbed water can get trapped between the fiberglass layers and the gel coat, leading to visible bubbles or swelling on the pool surface.
Gel Coat Damage:
The gel coat, which is the outer protective layer of the fiberglass pool, acts as a barrier to protect the fiberglass material. If osmosis occurs, the absorbed water can damage the gel coat over time, making it less effective at protecting the pool and potentially leading to discoloration or fading of the surface.
Structural Integrity:
Prolonged exposure to osmosis can weaken the fiberglass structure, leading to cracks, delamination (separation between layers), or other structural issues.
Common Causes of Osmosis in Fiberglass Pools
High groundwater levels: If the pool is surrounded by high levels of groundwater (for example, after heavy rainfall or flooding), osmosis is more likely to occur. This is because the pressure difference between the pool’s water and the surrounding water can cause absorption through the pool’s surface.
Improper sealing: If the pool’s gel coat is damaged, cracked, or poorly maintained, it can allow water to penetrate and cause osmosis.
Floodwater exposure: If a pool is exposed to floodwaters, which often contain contaminants and debris, osmosis may occur as the surrounding water exerts pressure on the fiberglass shell.
How to Prevent and Address Osmosis in Fiberglass Pools
Proper Pool Installation:
Ensure that the pool is properly installed and that the surrounding ground is adequately prepared. If groundwater is an issue, proper drainage systems should be in place to direct water away from the pool.
Inspect and Repair the Gel Coat:
Regularly inspect the fiberglass pool for any cracks or damage in the gel coat. Promptly repair any chips or cracks with a suitable fiberglass repair kit to maintain the integrity of the surface.
Control Groundwater Pressure:
If groundwater levels are high around your pool, you may need to consider professional drainage solutions to reduce the pressure on the pool walls. In some cases, installing a French drain or another form of water diversion may help.
Maintain Proper Pool Chemistry:
Maintaining balanced water chemistry helps protect the pool’s surface and keeps the gel coat in good condition. Be sure to keep pH, alkalinity, and calcium hardness levels in check to prevent further damage to the pool surface.
Monitoring After Flooding:
If your pool has been exposed to floodwater, it’s important to monitor the fiberglass shell for signs of blistering or bubbling after cleaning and restoring the pool. If you see any signs of damage, addressing it quickly can help prevent further deterioration.
What to Do If You Have Osmosis-Related Damage
If you suspect that your fiberglass pool is experiencing osmosis, it’s a good idea to consult a professional pool technician. They can assess the severity of the damage, determine if there’s any structural compromise, and recommend appropriate repairs. In severe cases, you may need to consider resurfacing or re-coating the pool.
By addressing osmosis early, you can help preserve the longevity of your fiberglass pool and ensure it stays in good condition for years to come.
Swimming in a pool with osmosis is generally not recommended for several reasons, primarily because osmosis can lead to structural and surface damage to the pool, which can pose risks. Here's why:
1. Structural Integrity Issues
Blistering or Bubbling: Osmosis can cause blisters or bubbles to form underneath the pool’s surface, which may cause the gel coat to weaken or peel. If the integrity of the surface is compromised, the pool could become rough or uneven, potentially leading to skin abrasions or other injuries while swimming.
Gel Coat Damage: The gel coat, which serves as the protective outer layer of a fiberglass pool, could be damaged by osmosis. A weakened or cracked gel coat might expose the fiberglass underneath, which can be rough and uncomfortable for swimmers, as well as more prone to further deterioration.
2. Chemical and Contaminant Risks
Osmosis often occurs in pools that have been exposed to external water sources like groundwater or floodwater. These sources may introduce harmful bacteria, debris, or chemicals into the pool, which could make the water unsafe to swim in.
Even if the pool is treated with chemicals, the absorbed water could contain contaminants that pose health risks, especially if the osmosis is severe.
3. Water Quality Concerns
Floodwaters, in particular, can carry harmful contaminants like bacteria, pathogens, and pollutants. Even after cleaning and chlorinating the pool, osmosis could allow for trapped contaminants to seep back into the pool water, leading to potential health risks for swimmers.
4. Long-Term Pool Health
While swimming in a pool with minor signs of osmosis might not pose an immediate health risk, allowing the condition to worsen can cause long-term damage to the pool, which could result in expensive repairs or the need for a full resurfacing.
What to Do If You Suspect Osmosis:
If you suspect that your fiberglass pool has osmosis, it's best to avoid swimming in it until the issue is resolved. Here's what you should do:
Assess the Damage: Check for visible signs of blisters or bubbles on the pool’s surface.
Contact a Professional: It's advisable to contact a pool technician to assess the severity of the osmosis. They can help determine whether the damage is minor or if it requires repairs.
Ensure Water Quality: Even after repairing any surface damage, make sure the pool water is properly treated and balanced to ensure it's safe for swimming.
In conclusion, it's better to err on the side of caution and avoid swimming in a pool with visible osmosis or any signs of structural damage until it’s fully repaired and the water quality is safe.