spots in my saltwater pool and spa

[tfp_fan]

I noticed these spots in my saltwater pool and spa. Considering my test result (TF-100), I don't think the current chlorine level in my pool is low; and I guess they happened a while ago probably when the chlorine level had been low. I am wondering if there is any way to remove them? I am new in pool maintaining and I do appreciate it if you could help me. @Texas Splash

 

[mknauss]

Can you brush those away?

I suggest you check for iron. Take a handful of Vitamin C tablets, put them in a thin sock, crush them a bit, and hold it on the area of the stain for a few minutes. If it disappears, it is iron. Houston water is known to have iron in it.

 

[tfp_fan]

Can you brush those away?

I suggest you check for iron. Take a handful of Vitamin C tablets, put them in a thin sock, crush them a bit, and hold it on the area of the stain for a few minutes. If it disappears, it is iron. Houston water is known to have iron in it.

Thank you Marty. I will try it with Vitamin C tablets. Regarding the spot next to the pool light, isn't it algea? I think it happened when saltwater chlorinator went off for a period of time once in the past.

 

[mknauss]

Regarding the spot next to the pool light, isn't it algea?

Does it brush away?
Looks like rust coming from inside the light.

 

[Dirk]

How old is your pool?

Those spots look like one I had, that turned out to be metal in the plaster mix. Iron, probably. My five-year pebble warranty was still in effect, so I called the installer. They sent a guy out who got in the pool. I walked away for a minute and by the time I got back it was fixed, so I never did get to see what he did.

Iron can sneak into the pebble mixture somewhere along the way: at the original quarry, or in transit, during installation or elsewhere. If it's a small piece of metal embedded in the plaster itself, or in one of the pebbles, the remedies above will only be temporary (but certainly worth trying). If you've still got a warranty, call the original installer and let them fix it.

If the strains keep coming back and you're out of warranty, it might be worth having a plaster guy take a look.

 

[Toxophilite]

In this area, especially red dirt north Houston, any small clay ball or sand ball will rust spot right on top of your driveway.