The new pool with rust saga continues. The coping stones were mortared to the lid trays. One of the trays has been left uncovered and now is covered in rust. I thought the coping stones were supposed to be lifted off of the lid trays and then the lid tray could be opened. Any ideas on why this could be rusting so badly? The trays have been there less than a month. Before I had rust spots in the pool and it was thought that it may be from the landscapers metal blade- they resolved with vitamin C tablets and metal out. Is this something the landscapers should’ve known not to use?