White splotches, spots, and lines (stains/fading?) in 3 year old fiberglass pool

[viking]

I have white random splotches and spots (resemble water splash markings), and lines in my 3 year old fiberglass pool. There is actually a perfect white faded looking line that goes around the bottom perimeter of the pool along with lines going the width of the pool here and there. At first I thought the color was fading because of these suspicious lines. I contacted the manufacturer. They sent one of their guys who said he had just left a pool with the same problem...calcium scaling. After speaking to his boss on the phone, he performed an acid wash using a descaler and acid. Instructions were to leave the filter off for 24 hours, then run the filter for 24 hours. After this process, there was no improvement! The person in charge of service for the manufacturer said it would take time, and the process may have to be repeated along with scrubbing the pool and spa. (problem is in both) That was almost 2 months ago. Since the acid wash, our pool guy set a descaling plan for us.... keep the ph at 7.2 and chlorine at 2, add a descaler weekly and no shocking. He said that this would slowly remove the "scale".
Today another pool company came out to look at a different issue, and took a look at our "scale". He has been installing (gunite) pools for 25 years or so and has experience with scale which he said is rough and can flake off. He was baffled. Whatever it is we have is smooth to the touch, just as smooth as the pool surface itself. There is no way to scrape it off. When the spa was drained, the "white stains" became snow white (no longer hydrated) and had a slight chalky residue when rubbed hard. I am so confused! Is this scale or not? Where do we go from here? It is so frustrating. I just made another call to the manufacturer for further assistance. I did send pics of the lines, etc. and the "white" drained spa to them initially.

[aylad]

Hi,

I'm not the person that can answer your question, but the ones that can should be by shortly. I will tell you this, though--one of the first things they'll ask for is a set of test results on your water, taken with drop-based testing, and a list of what chemicals (ingredients, not product names) have been put into the pool. With that info, hopefully somebody can give you some good info to help solve the problem!

You can also use the google search linked in my sig to search the forum for other posts regarding the same problem--you'll just have to log out to read the responding threads until your registration is upgraded by the forum's owner, Ben.

Welcome to the forum!

[viking]

Thanks! I retyped and posted this twice because it said I wasn't logged in the first time. Sorry. I am getting the info now.

[aylad]

I deleted your other, duplicate post. When new posters put posts up, they go into a queue to wait for a moderator to approve them before they show up on the forum. It's one of the steps in place to keep hackers/spammers out of the forum. One of us is almost always on the forum, so usually you don't have to wait long to see your post show up, but I guess we were all off at the same time last night!

[PoolDoc]

Hi Viking;

I don't know the answer to your question, but I have some ideas. However, I'm going to ask Waterbear, who's worked with FG pools, to see if he has any ideas -- you may have to wait for his reply; he's sorta on vacation this week.

Meanwhile, please
(a) send me those pictures -- poolforum@gmail.com,
(b) get some Vitamin C tabs, and put some on some areas that are NOT white, and see if they lighten up.
(c) also, sit a small pile of them on WHITE faded area, and see if they have any effect over a 24 hour period.

[viking]

Thanks for the reply. This morning I tried scrubbing a white splotch, after much effort, it lightened just a tad but is still there. It's as though it's part of the pool surface, like a rust stain would feel. It is completely smooth. I applied a descaler to it and scrubbed. I also applied 50/50 concentrations of m acid....no change! I am so disouraged.

I have a correction to make....my pool is ONLY 2 years old, not 3. Also, if it helps, I live in South Louisiana.

How do you suggest I apply the Vitamin C tabs? (I lowered the water level in the spa to expose/dry some of the staining.)

Thanks! This is consuming my time.

==========================================

I emailed some pics to you. Also, I just dropped a few C tabs in affected and non-affected area in the spa, which will be easier for me to monitor.

Thanks bunches!

[viking]

I have a salt water pool, just under 20,000 gallons.
Test results today:
TC 1
FC 1
TA 81
TH 192
PH 7.6
CYA 114
Ph has typically been about 7.2.

We have been adding 6 oz of descaler per week after initial dose of 64 oz. 3 weeks ago, 1 cup m. acid every 3-4 days for descaling, and a couple 3 inch tabs in skimmer every few days for chlorine. (pool guy instructions for descaling)
Today AFTER these results, added 1 cup m. acid and 1 lb of a stabilized chlorinator (with no calcium) as a shock due to algae as a result of low chlorine. Recently added a phosphate remover (phosphates were about 2,000)
***Considering discontinuing descaling treatment....not positive that is the problem.