Hello, I have an 18,000 gallon all fiberglass rectangular pool installed in 2008 manufactured by a company out of Louisiana. At 14 years old, the gelcoat on my fiberglass pool just started blistering this year all over the steps and along one of the long walls of the pool. Over the last 14 years, I have maintained my pool chemistry as per hayward recommendations for water chemistry. We have a saltwater generator and keep the salt level between 2700 and 3000. The calcium hardness has been kept at 220 to 240. After speaking with one of the representatives from the pool manufacturing company about what we could do to fix the blisters, they recommended that we get rid of the salt water and increase the calcium hardness to 350. They said we would see the blisters disappear after applying their recommended fixes. Question to anyone out there that has had a similar experience. Once the blisters have already appeared, will increasing my calcium hardness and removing the saltwater make the blisters disappear? I'm not convinced that this can be fixed thru changing the water chemistry after damage has already been done. Thanks!
Fiberglass Pool blistering fixed by increasing CH and removing Salt water?
- Thread starter jkpool
- Start date
The ocean is at least 10 times as saline as your pool water concentration. Fiberglass boats spend years in it without the gel coat blistering with a little care. Tears are typically 1% salt, 10,000ppm, 3+ times as salty as your pool, and wouldn't damage fiberglass.
Not likely salt water is causing the problem.
Not likely salt water is causing the problem.
- May 27, 2021
- 1,254
- Pool Size
- 17000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
There is plenty of information on GRP blistering or Osmotic blistering with fiberglass pools. Google it and read up. The information you will find does not correlate to failure either due to salt water or calcium hardness.
I have a 38 old hybrid pool that suffers from them. It was a ”freshwater” pool until I converted it to a SWG 2 years ago. I’d postulate that this 36 year test rules out the assumption of saltwater that the manufacturer of your pool claims is a factor. If it was a factor, my pool would have been blister free when I bought it.
As an aside does the manufacturer know that salt builds in a pool over time through traditional chlorination methods? How does that cumulative effect of salination over time impact their claims? How should a pool owner combat this effect to prevent blistering?
edited to add….in short no you can’t fix it in the way they claim.
I have a 38 old hybrid pool that suffers from them. It was a ”freshwater” pool until I converted it to a SWG 2 years ago. I’d postulate that this 36 year test rules out the assumption of saltwater that the manufacturer of your pool claims is a factor. If it was a factor, my pool would have been blister free when I bought it.
As an aside does the manufacturer know that salt builds in a pool over time through traditional chlorination methods? How does that cumulative effect of salination over time impact their claims? How should a pool owner combat this effect to prevent blistering?
edited to add….in short no you can’t fix it in the way they claim.
gingrbredman
Gold Supporter
- Jun 10, 2020
- 732
- Pool Size
- 11200
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
If the manufacturer is saying the sat water is the reason for the failure, and a "freshwater" pool is the solution, then what happens in a little time when the pool has the same salinity as you do now? 2,700 to 3,000 ppm of salt is not high at all, and would venture to say a liquid chlorinated pool over time would have the same values. The addition of chlorine and muriatic acid over time will add salt, so what then? Drain and re-fill again?
That's complete nonsense.
The blisters are not going to disappear simply by changing the water chemistry.
