Fiberglass Pool Chemistry with Winter Freezing?

GrandizerGo

Well-known member
Jun 21, 2019
64
Ontario, Canada
Pool Size
11000
Surface
Fiberglass
Chlorine
Liquid Chlorine
For those in the northern climates, how are you preparing for the upcoming temperature drops? While engaged in chemical warfare I'm not sure what levels I should be aiming for. Looking at the fiberglass manufacturer's recommendations for warranty status it seems impossible to maintain those levels and have balanced water. Even more so with salt water pools.
 
Looking at the fiberglass manufacturer's recommendations for warranty status it seems impossible to maintain those levels and have balanced water.
And you probably never will. Those generic manufacturer levels are out of touch with pool conditions around the country, unfortunately it's their way of trying to hold pool owners accountable. Very frustrating. When you close, you have two main concerns: protecting the hardware of your pool (freezing) and water chemistry to help avoid algae next spring. While no one wants to see a green pool in the spring, protecting your investment is #1.

The link below still applies to you and is a great place to start.

 
Equipment can be replaced and algae can be killed. I'm more concerned about damage to the gel coat or shell as that would be much more difficult to fix. Do gel coat issues happen because of unbalanced water or because even though the water is balanced it is outside the recommended specs?
 
Do gel coat issues happen because of unbalanced water or because even though the water is balanced it is outside the recommended specs?

Today's FB shells are extremely durable and very unlikely to become damaged from winter or any other seasonal change. Most FB shell damage occurs from a poor installation.

We typically see gelcoats with damage/changes from either of the following:
- Chemical levels allowed to sway "extremely" outside standard TFP levels (i.e. scale or staining)
- Potential manufacture defect in gelcoat fabrication or application
- Unknown anomalies/age

In some cases, the reasons for the changes in gelcoat are somewhen obvious, while in others it's a complete mystery. Ask any marine retailer and/or some of our TFP chemist experts and they'll tell you that FB, by its very nature, is expected to fade/oxidize over time. If it does, it's a cosmetic issue and has nothing to do with the shell's structural reliability. Still, we see some owners (like myself) who's gelcoat became chalky in a relatively short period of time, while other TFP members have a gelcoat close to 10 years old and looks as fresh as the day it was dropped into the ground. TFP chemical levels all maintained the same with no real explanation for the changes in some pools.
 
<rant>
It bothers me that these companies sell in regions were the temperatures fluctuate. Their levels are unattainable and their warranty conditions leave too many outs. I saw part of a warranty that said you had to notify them if you plan to lower the water below skimmer level (so every winter) and cant have the water overflow over the top (so better pump the water out if you get a bad storm). That combined with poor pool store testing and the requirement for third party records...I was kind of ****** when I got my ph to 7.6 and test with both the Taylor drop test and a digital meter just for the store to get 7.8 on their readings. The whole thing has turned me off to FG. It looks beautiful but the ability to replace a liner if it goes bad is the single most compelling reason why I would steer people away from FG given that manufacturers don't properly support their products. If this shell goes bad I'm stuck with it and getting a new pool would be crazy expensive. If a liner goes bad I just replace it and its much cheaper than fixing FG gelcoat issues.
</rant>
 
I hear ya - 100%. The pool and FG industry has owner's with their hands tied for sure. But to be fair (just a little), as a business they have to provide "some" sort of standardization in the manual, so they use the generic pool industry levels. Without "something" as guidance, you can imagine all the FG owners who really never care for their water at all, then claim a warranty issue one year later. I'm not defending them, but they have to publish some guidance. Unfortunately, they don't recognize some of the very obvious chemical adjustments necessary for certain climates, equipment, or types of chlorination. Would you believe my Viking manual states to test TA every 4-6 weeks, CH every 2-3 months, and CYA every six months? That on top of the ridiculous "recommended levels" they prescribe. Oh, and here's the kicker from the manual .... "Water which is perfectly acceptable for household use may be totally unacceptable for your pool. This is the reason your pool water must be professionally tested and balanced every six to eight weeks." Bwahaahaaaa!

But, TFP care keeps our water crystal clear. We enjoy our FG pool very much, and any cosmetic issues do no take away from our enjoyment each season. Each pool type has its pros & cons, but for us, FG was the choice in-part because it was economical and we have lots of dogs. I could just see the first set of claws digging into a liner, and our soil stinks in this area (moving clay).

The TFP Recommended Levels are proven to be safe and effective for FG. If you have concerns for your warranty, all you have to do is follow your manual requirements for periodic testing. I'm sure that's something you can adjust and have done as needed just in case.
 
  • Like
Reactions: Newdude
So going back to the winterizing, is everyone jacking up their calcium as we get closer to freezing temps? Bumping TA and letting PH drift up more? With a pool that is stable now then something has to give to be balanced as temp is dropping. How often are you guys testing the water in the winter months?
 
No need to get radical with levels. The two biggest influences on your water chemistry this winter will be water temp and pH as they relate to the potential for scale. Fortunately, they closely cancel each other out. When the water gets cold, the pH begins naturally to rise, but the lower water temp lowers the CSI which helps to balance it out. You can see those effects by playing around with the PoolMath APP and experimenting with water temp changes. No need to add CH or manipulate TA out of the norm. Just stick to the TFP recommended levels and you should be fine.

As for the algae prevention, follow the instructions from the link in Post #2 above and you should do well. Close as late as you can to ensure the water is cold and remains that way, then open as soon as you can next spring.
 
@Texas Splash based on playing with the Pool Math levels I don't need to worry about scaling but rather being too negative on the scale. Seems like if the temp dropped to 32F tomorrow I would need to increase TA and CH to not be too negative. Having salt in the pool makes the numbers even worse.
 
Seems like if the temp dropped to 32F tomorrow I would need to increase TA and CH to not be too negative. Having salt in the pool makes the numbers even worse.
For plaster pools that is true. Extremely low water temps can make for a very low CSI. But for all practical purposes, FG and vinyl don't use plaster in their products anymore, so there is no calcium to be eroded or leach-outwards. This is why the CH minimum level is so low. In fact, the main reason there is a minimum CH level for FG is primarily to prevent staining.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.