Regular water changes are critical to maintaining a healthy underwater environment. In addition to replenishing trace elements absorbed by inhabitants or other biological processes, water changes reduce nitrate levels which are constantly increasing due to fecal decomposition and plant activity. In a balanced marine, reef, or freshwater aquarium, one that is not over-stocked and is equipped with a quality filtration system, water changes may be done monthly. For garden aquariums, weekly changes are best to replace the trace elements consumed by hungry plants.
Although every aquarist is well aware of the importance of regular water changes, not everyone changes their water as frequently as necessary because of the unpleasantness of the task. The usual tools - buckets, scrapers, brushes and more - are awkward to use. Buckets are heavy. Spills go with the territory. And dirty gravel smells bad. But perhaps the worst problem associated with a traditional water change is the stress it places on fish.
In recent years a number of innovative products have made water changes easier on you, and less stressful on your fish:
If you have a pure source, an automatic water changer can be used to filter incoming water while draining existing water.
While all of these products do an excellent job for the purpose for which they were designed, another solution, the Python No Spill Clean 'N Fill, has received the most attention.
Hooked to your faucet with a two-way valve, the Python uses water pressure to siphon water from your aquarium and efficiently vacuum gravel. Most importantly, it removes water and debris without stressing your fish or aggressively churning up the water. The cleaning action is done inside an isolation chamber where the gravel is suctioned up then tumbles back down. Waste material is loosened in the churning action inside the chamber and siphoned away. You direct the chamber from one small area to the next till the job is complete. It's fast, extremely easy-to use, and does an excellent job of cleaning your gravel while changing your water.
Years ago, traditional water changes required removing all of the water and relocating your fish. With the Python, it is possible to do the same or better cleaning job by removing no more than 1/4 of the water. Freshwater aquariums can be easily re-filled. Using a floating thermometer you adjust the tap water to match your aquarium temperature, and then flip a valve to refill. Saltwater changes are almost as easy, but require careful preparation of replacement water. Of course, always remember to treat your new water to neutralize chlorine and other toxic elements.