Rust leaking out of skimmer

[beanPoolOwner]

I have a lot of rust developing around my skimmer:

I removed the inside white plaque and saw the screws' heads were rusty.

I will replace the screw, but I wonder if that could be a symptom of another problem, like the skimmer not being sealed correctly, or something like that?

[Teapot1]

Doubtful, more likely water chemistry, aggresive water on the langlier saturation index.
Have you some water test results we can see?
Also the screws can be low grade stainless so use titanium or 316 stainless steel.

[beanPoolOwner]

Understood, I will buy a water test strip to measure iron and check.
The only test strips I have right now measure pH, alkalinity and chlorine levels. These levels are all fine.

Thanks a lot @Teapot1 for your insight.

[Teapot1]

Sadly test strips are wildly innacurate, yes you get a colour change but often very far out. The tests you have on your strips are the ones we need but accurate from a proper test.
pH, Alkalinity, calcium hardness, chlorine levels and CYA. Also the temperature of the water.