"Rust" spots appearing on the bottom

[PoolGate]

I am not sure what is going on but I am noticing these spots. They appear to be rust spots. Running over them with the robot and the brush doesn't do anything to them.

I've circled a few of the areas in red in the below pics. I left a pump in too long and it made one rust spot I know where that came from but the others seem to be popping up in random locations. None on the sundeck though.

 

[kimkats]

Try some cheap, white vit c tablets. If you need to you can crush them up and put them in a thin sock to get them to sit on the stains. Let us know how that goes.

Kim

 

[sbalberti]

A lot of fertilizers have iron in them. Make sure when you fertilize it doesn't get slung into the pool because that'll cause rust spots like you're talking about.

 

[PoolGate]

Try some cheap, white vit c tablets. If you need to you can crush them up and put them in a thin sock to get them to sit on the stains. Let us know how that goes.

Kim

I will try that hopefully that is it.

 

[Dirk]

A lot of fertilizers have iron in them. Make sure when you fertilize it doesn't get slung into the pool because that'll cause rust spots like you're talking about.

Oh, man! This is my "Learn of the Day!" I wouldn't think twice about doing just this. My lawn mowers (I can't bring myself to call them gardeners) would not think once about doing this. No more fertilizer twirly thingies in my yard!! Thanks!