Has anyone had success with dropping the pH in a fiberglass pool ( to pH 4) to remove widespread calcium stain? I have a pool with a white discoloration that appears to be within the gel coat, so possible calcium chloride penetrating the gel coat. Hypothetically, dropping the pH would cause the calcium chloride to be pulled out of the surface.
Aloha fiberglass calcium scale all over pool
- Thread starter Microjen
- Start date
- May 3, 2014
- 58,521
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Welcome to the forum!
Do you have a full set of test results you can post?
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
Do you have a full set of test results you can post?
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
- Jun 22, 2014
- 47,861
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Jen, we would definitely like to see a full set of results and possibly a historical patter of your levels if you can give us an average perhaps of where those levels have been over the past 1-2 years. Something to consider, not all discoloration in FB pools is due to calcium. Case in point - my pool.
See Fiberglass Discoloration (Faded & Chalky) - My Story
Welcome to TFP!
See Fiberglass Discoloration (Faded & Chalky) - My Story
Welcome to TFP!
While discolorations on fiberglass pools has been discussed here over time. Various manufacturers and various types of staining.
I don't believe we have ever found one reason or consensus on cause although it seems to be in the deep blue pools more than lighter colors?
I can't say I'd feel safe dropping my pH so low and worry it will damage equipment and the finish itself?
Maddie
I don't believe we have ever found one reason or consensus on cause although it seems to be in the deep blue pools more than lighter colors?
I can't say I'd feel safe dropping my pH so low and worry it will damage equipment and the finish itself?
Maddie
I had a chalky white substance on the walls of my fiberglass pool last year. I originally thought it was calcium scaling, but a fiberglass pool pro said that it was caused by low calcium and high PH. When I tested the water, the calcium level was only 100, and PH was 7.8. I increased the calcium level to 300 and started keeping my PH around 7.4-7.6 and the problem went away.
It took about a week. I increased my calcium levels gradually, instead of adding all of the calcium at once since I had to add a lot of calcium. After each calcium application, I brushed the walls and floor of the pool real well several times. Once I finally got to 300 ppm, the chalky white substance went away. I notice that if my CH level dips down below 250 ppm and my PH stays too high, the chalky white substance comes back so I really have to keep an eye on my CH and PH levels. I've also noticed that the chalking is worse if my PH stays too high, even if I have a desirable CH level. I have a feeling that my CH level was too low for many years because I didn't realize that calcium was important in a fiberglass pool until I joined this group and talked to the manufacturer of my pool. The guy at the pool store always told me that I didn't have to worry about low calcium since I had a fiberglass pool, which apparently isn't true according to the manufacturer of my fiberglass pool.
I've been working on mine with a similar issue that I hoped was a chemical imbalance for a couple of weeks and some days it seems a little better but I did not raise my CH above 225 ( when I noticed the issue my CH was 150-175). My PH has constantly drifted to 7.8 and then I would lower but even then I really only adjusted it 7.4 at the lowest, so average has been 7.6 -7.8. I have been on top of my PH since I noticed it, keeping it between 7.2-7.4 and alkalinity above 80 as my sales person says it should not be below 80 for gel coat finish. I will try CH to 300. Mine is more just lighter color and just not glossy smooth like above the water line. I have talked to another fiberglass expert with no vested interest but very well respected in the industry that thought I may have damaged my pool gel coat from too high chlorine and high ph as well when I explained some neglect over the winter. He didn't seem to think calcium scaling has a lot to do with calcium levels within reason as much high ph. In his opinion, as for damage to the gel coat, high CH and high PH together are the main culprits and very quickly. He said high CL alone over just a couple of years bleaches the color. His opinion high was above 5ppm but he said industry is above 3ppm. My pool is a gray color and I can't tell what could be just dull staining from leaves and organic material making some parts darker vs light color, with the lightest parts noticeable under water in the corners and creases. I know it is impossible to maintain a Free CL to industry standard with a CYA of 70 if you want that balance, I also know my FC did run at least 6ppm with CYA of 70 all year, TA 60-70 and with SWCG I'm always fighting a rising PH so when I neglected it during the winter months, I am afraid I did permanent damage and the expert I discussed it with believes its that high CL with high PH can cause that and within just a couple of months. I really was far more concerned with swimmer safety than the pool surface. Who knew? Certainly not me. So discouraged and wonder if I made the right decision going fiberglass. They may be arguably easier to maintain but the repercussions of mistakes and over a very short time seem far more irreparable. Kinda wish it could just be a gunite or plaster renovation. At least the pool would be back to new again. It certainly doesn't help that manufacturers, or mine at lease seem not to emphasize exactly the precautions to take until it's too late, explaining in hindsight and just blaming it on some unidentified negligence no matter the issue. They have to know exactly what can harm their product and just don't want to confuse their customers their "easiest to maintain sch-tick". Unless of course it inevitably happens to some amount of product due to manufacturer defect and then can always scapegoat chemical imbalance. Also wonder if there are people out there that have NO such issues with a fiberglass pool and have been following TFP protocol. I seem to be focused on the problems and it may have jaded me.
My FG pool is just over a year old. I followed TFP since the beginning. I opened my pool late March and found above the water line is a bright blue, but anything below the waterline has a white haze to it. Nothing I have done will remove the white haze. It is smooth and white. I'm at a loss of what to do.