Scaling From Excess Salt

[MrSiblini]

Yesterday I discovered what we believe is scaling caused by excess salt in my pool. I'm sharing it here to 1. Confirm that's the problem and 2. Better understand said problem, the damage it has caused, and my repair options

See attached photo for a visual. It has been running with excess salt (topped at 6k) for two weeks. I noticed the water was cloudy at the peak but cleared up as I've brought it down.

I thought I could slowly bring it down and the worst I was dealing with was a little dry skin. I used to swim in cold seawater so it didn't bother me.

Nobody at the pool store told me this was going to completely ruin my pool.

Here are some test results to help analyze this:

04/22 @ 8:45PM

Salt - 6200

Drained about 4 inches and refilled to dilute, salt went down to 5800.

04/26 5:15PM

Salt - 5200

04/29

Local Leslie location tested salt at 4709. This was the day I discovered the stains and took that phooto.

Additionally:

1. Calcium was low at 192

2. Metals are low/no.

Tested again after a small dilution.

Salt - 4600

Used waste setting to pump out water and refill twice. After the 1st refill, salt was reading at about 4300 this morning, 04/30. It is currently on a 4 hour cycle since I topped it off again after that initial test reading.

So current salt = approx. 4300

Will test one more time at the end of the cycle, then do another drain/refill.

Additional info:

Chlorine and Ph have been kept consistent during this time. TA floats around 60-80 which seems to work for my pool.

The pool is 10,500 gallons, fiberglass in-ground. It is a saltwater pool, needless to say.

The pump, salt element, and filter were replaced a couple of weeks ago (around the time we found it had high salt - I sort of misunderstood their words and added way too much).

I am in Middle Tennessee about an hour south of Nashville.

All testing was conducted using the kit recommended by TFP using reagents, unless otherwise noted. I am attaching a photo of the test from the store as well.

Some of the stain in the photo has also been removed via rubbing a vitamin C tablet on it (airbourne from a local pharmacy). Not all of it, however.

TFP community, would you be able to help me understand the following?

1. What is the extent of the damage caused here. Is this going to eat through the pool and ruin it?

2. What exactly happens with high salt that causes these stains to appear? Especially when calcium is low and metals are 0.

I have long wanted to have a pool. I was able to make a ton of progress and get it running thanks to some of that stuff I found on here already, including the test kit. But this caused me extreme concern yesterday evening and the know-nothings at these pool stores said some things that raised my alarm even higher.

 

[mknauss]

Welcome to the forum.

Salt will not create scale. And the level of salt you show in the pool water is not an issue other than it does not need to be that high to operate the SWCG.

Is the dark spot what you are concerned with? It is raised? Might be an iron stain. Try a hand ful of vitamin C tablets in a sock and put it on the spot for a few minutes.

 

[Jimrahbe]

Dainel,

Did you use Clorox Salt?

Did you just dump it in the pool, and hope it would dissolve, or did you sweep it around until it did dissolve?

I don't think adding salt itself had anything to do with the problem in the pic, except something else may have been mixed in with the salt.

Thanks,

Jim R.

 

[MrSiblini]

Both informative answers. Thank you both.

"Did you use Clorox Salt?

Did you just dump it in the pool, and hope it would dissolve, or did you sweep it around until it did dissolve?"

No - it was Diamond branded specifically for pool salt. I have tried a few different locations and found that the shallow end by a fixed jet is the best place to add stuff. Dissolves on its own fairly quickly but I usually agitate it a bit to help it along.


"Is the dark spot what you are concerned with? It is raised? Might be an iron stain. Try a hand full of vitamin C tablets in a sock and put it on the spot for a few minutes."

Yes, those appeared within the last few days. The store thought it was iron or other metal as well, but all tests indicate little to no metals in the water. Just very high salt.

Rubbing vitamin C did mostly remove the one photo'd.

So here's the real concern now - if it's not the salt, and my metals are low, where did these spots come from? There was the large one pictured, another large one in the opposite corner of the pool, and several others scattered around the pool along the path of the water current.


ALSO: I should add that the salt was added weeks ago. These spots only just started to show up.

 

[mknauss]

Something fell into the pool is likely. Fertilizer, building material, etc. Anything like that?

 

[MrSiblini]

Something fell into the pool is likely. Fertilizer, building material, etc. Anything like that?

1. The hose I am using to top it off has a metal end that's in the pool during the refill

2. My dog was learning to swim and wore a harness with a few small metal rings on it


Those were my thoughts when metal was suggested. Is it possible or likely one or both of those things stained the pool even without raising the PPM of metals in said pool?

 

[mknauss]

Not likely those items unless you left them in the pool for some time.

Metals in the water do not cause that type of stain.

I would put a handful of vitamin C tablets in a sock, crush them up a bit, and set it on the stain. Let it sit for several minutes.

 

[MrSiblini]

Not likely those items unless you left them in the pool for some time.

Metals in the water do not cause that type of stain.

I would put a handful of vitamin C tablets in a sock, crush them up a bit, and set it on the stain. Let it sit for several minutes.

I will do that. Should I be concerned about further damage to my pool based on current levels?

 

[mknauss]

When you get your own proper test kit, post up the results.

 

[MrSiblini]

When you get your own proper test kit, post up the results.

I have the test kit recommended by TFP; my proper test results are in the original post.

I did just try and use some tablets inside the sock. Here's what the stain looks like after.

The part that's left feels almost like it's beneath the blue layer of the fiberglass, like paint pitting on a car.

 

[MrSiblini]

Not likely those items unless you left them in the pool for some time.

Metals in the water do not cause that type of stain.

I would put a handful of vitamin C tablets in a sock, crush them up a bit, and set it on the stain. Let it sit for several minutes.

Follow up - if not metals, then what does cause this kind of stain/pitting in the fiberglass?

 

[mknauss]

I'm sorry, you attached a Pool Store test sheet ---
Please put test results like this
FC
CC
pH
TA
CH
CYA

And the CH result was not from your kit.

As far as the stain, hard to say. If it is below the gel coat, it is an anomaly in the shell. You can contact the manufacturer for advice.

 

[MrSiblini]

I'm sorry, you attached a Pool Store test sheet ---
Please put test results like this
FC
CC
pH
TA
CH
CYA

And the CH result was not from your kit.

As far as the stain, hard to say. If it is below the gel coat, it is an anomaly in the shell. You can contact the manufacturer for advice.

Any idea how to ID the manufacturer if I just bought this house and it came with the pool?

 

[mknauss]

Any idea how old the pool might be?

 

[MrSiblini]

Any idea how old the pool might be?

2-3 years, according to neighbors who saw it being installed.

My big concern is that there is something radically wrong here and that I am running out of time to save my pool. What do I have to do to prevent my pool from being damaged beyond repair or use with these spots suddenly appearing on it?

There is one other large one on the other corner of the pool, as well as a few smaller ones scattered round the deeper end of the pool.

 

[mknauss]

I would doubt it would damage the integrity of the shell.

Staining like that is not usual. I would take a hard look around, including your neighbors, to see if anything could have gotten in the pool.

As far as the manufacturer, I have not seen any stamp or other indicator on our fiberglass pool. Ours is a San Juan pool. Latham is a very big manufacturer.

 

[MrSiblini]

I would doubt it would damage the integrity of the shell.

Staining like that is not usual. I would take a hard look around, including your neighbors, to see if anything could have gotten in the pool.

As far as the manufacturer, I have not seen any stamp or other indicator on our fiberglass pool. Ours is a San Juan pool. Latham is a very big manufacturer.

That's a little reassuring.

My dogs toys have been in the pool as well. They float. But they are well-used. Could something have been on those that caused this?

 

[mknauss]

Not likely. Keep an eye on the stains. There is a thing called Cobalt staining, but does not present itself like you are showing.

 

[MrSiblini]

So just watch it and otherwise keep using it?

Worst case scenario the stain spreads and has to be cleaned?

 

[mknauss]

No problem using the pool. The stain is just cosmetic.

If conditions change, post back here.

You might try to do some investigation on the manufacturer of the pool. Check local pool companies for whom installed the pool. The shell should have a warranty.