To keep the fish and other marine life in your saltwater aquarium happy and healthy, you have to do some basic maintenance. Some tasks you need to do every day without fail; other jobs you do weekly, bi-weekly, or monthly. And every three months you need to conduct a thorough examination of all aquarium systems, including lighting, heating, filtration, aeration pumps, and tubing. Replace or clean parts as needed.

The following table shows the tasks to do on a continuing basis:

Every Day Once a Week Every Two Weeks Every Month
Turn the query lights on and off. Most aquarists prefer to use an automatic timer. If you choose not to, try to turn the lights on and off in a consistent pattern. Remove excess algae Clean filters as needed. Partially change or rinse the filter media on some filters, if the bioload is high, the media is dirty, or the flow is restricted. Conduct thorough filter checks. Replace the filter carbon and rinse the filter media and components, as needed and depending on bioload.
Check for fish and invertebrates for signs of stress, diseased, or death. Be prepared to remove or treat fish that aren’t well. Clean the glass Change twenty percent of the tank water while vacuuming the gravel. Clean the protein skimmer.
Feed the fishes and invertebrates twice a day, removing any uneaten food. Conduct water tests weekly after the water matures and the nitrogen cycle is established. Record all test results and add trace elements and buffers. Replace air stones as needed.
Conduct water tests until the water matures and the nitrogen cycle is established. Routine tests include ammonia, nitrite, nitrate, and pH. Record the test results. Remove excess algae. Clean the outside of the aquarium, removing salt and calcium deposits, dust, and dirt.
Check the water temperature and specific gravity or salinity. Adjust the heater as needed. Rinse any tape decorations that suffer from excess algae.
Empty the protein skimmer collection cup as needed.
Check the water level and top off as needed.
Check all aquarium systems: heater, filters, aerators, protein skimmer. Make sure they’re running properly and smoothly and pay special attention to intakes and siphon tubes. Make sure nothing is leaking.