Water mixing containers can become coated with all sorts of things like calcium deposits or algae. Every once in a while, it might be a good idea to completely clean out these mixing containers, making sure to remove anything that could foul up your next batch of saltwater. To do this, you can use pressurized water, bleach, or vinegar. Pressurized water and vinegar are my preferred choices, but sometimes those containers get really dirty and need something with a little more kick. If you do use bleach, make sure to wash and rinse the container multiple times after it has been cleaned. This will ensure all of the leftover bleach has been removed or diluted to the point it won’t negatively impact your aquarium after a water change.