When you get into this hobby there are certain tools that go along with maintaining the aquarium system. Using the correct tools and keeping them in top shape will make you job easier. Unfortunately most tools are taken for granted and deteriorate. This is especially critical when working around with a corrosive liquid such as saltwater, and some organic biofilms.
Most common reefing tools are usually made of stainless steel or some type of plastic. There are specific actions you need to perform for each type of material. The toughest to deal with is rust on metal tools.
For example, the most common items I have been using to maintain my saltwater aquarium are algae scrapers, bone cutters, various dental scrapers/picks, and many lengths of tweezers. Many of my favorite low cost tools are made of stainless steel. All metal will rust to some extent so the basics are to rinse with fresh water and dry after each use but even that rust will still occur. Every so often if the rust gets out of hand I would wire brush (brass brush preferred since it is softer) all my tools with a rotary tool or bench grinder. This will coarsely remove the rust. If you want to go a step further I would buff the surface with a polish. But typically I will just take it after wire brushing and coat the surface with a 100% silicone lubricant since it’s reef safe and used on most O-rings in many filtration products to help protect it.
After the proper cleaning ensure that the tools are stored appropriately in a dry spot. Proper air circulation and dehumidification in the fish room or wherever you store your tools will also help reduce the corrosion rate. These simple steps will help preserve your tools for as long as you are in this hobby and help preserve your precious funds for more important items like livestock.