When prepping for a water change, be sure to cover the container or containers in which the new saltwater is mixing. If left uncovered, not only can water splash out onto the floor, but other stuff is bound to get in. Dust, bugs, and hair can all find their way into a freshly mixed batch of saltwater, and while they probably have little to no impact on the quality of the water, they are still things you don’t want to be adding to your aquarium. So, be sure to cover each and every bucket, trashcan, or whatever container you use. If the water does become contaminated with various particles, you can remove them with a net or a filter sock. You could also filter the water through a filter sock as it enters into the aquarium.