We've had our pool up and running for about 2months and I'm beginning to see signs of rust on my Hayward skimmer mouth screws as well as on the pool ladder where the treads attach to the verticle rods. I'm wondering 2 things: Is this normal? Do pool hardware companies design separate freshwater and saltwater kits? If so, I'm wondering if I got a freshwater version by mistake. The pipes on the ladder look like stainless steel but marine grade stainless shouldn't rust and definitely not in 2months. Most of the oxidation is occuring near the waterline. Screws below the water's surface look a bit better. Pool balance has been spot on the entire time. PH between 7.4 - 7.8, FC at 5.5.