The slowest and most tedious part about performing a water change on your aquarium isn’t the actual process of removing and replacing water, but making the water itself. Since tap water is laced with contaminants, making your own pure water from a reverse osmosis filter is the only way to get clean water into your aquarium. But RO/DI units aren’t all that efficient and they take forever to make enough water to do your water change. Most of these filters crank out a whopping 75-100 gallons per day, and even after the proper amount has been collected, you still have to mix in the salt and let it stabilize for an extended period of time. To help make the most of your time, run your RO unit at night while you sleep so that the next day while you’re at work, your salt can mix. Then, when you get home that evening, you’re ready to perform your water change, assuming the parameters of the new saltwater all check out.