Marine Aquarium Maintenance Tasks and Schedule

Fish in fish tank
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Maintaining water quality in a saltwater aquarium is critical for the health of the fish. Aside from the normal day-to-day upkeep (checking water temperature, feeding animals, overall observations and water top-off), saltwater aquariums and all of their components require periodic maintenance and cleaning in order to function properly.

The best schedule for major cleaning chores depends on your system type. While true Berlin live rock and Jaubert/plenum filter systems need little maintenance, wet/dry trickle and canister filters require more frequent attention. There are a number of factors that affect how often your tank will require maintenance:

  • Filtration type
  • Biological load on the filtration system
  • Quantity and types of foods used
  • Inclusion of tank janitors
  • Use of toxin (nitrate and phosphate) reducing products

Once your aquarium is cycled, weekly water quality tests will indicate when a thorough cleaning is needed. Over time, you will start to see trends in your water test readings as well as observable changes in your aquarium inhabitants.

Observing Your Tank

Taking a couple of minutes every day to look carefully at your aquarium will pay big dividends. Get into the habit of checking the following items and be sure to record your observations of anything unusual in your tank log book:



  • Activity
  • Eating

Tank janitors

  • Activity
  • Keeping up with cleaning


  • Color
  • Open



Testing Your Aquarium Water

Test your water parameters (including Normal Sea Water values and target water test levels) at least once per week, to begin with. Slight changes in some tests are normal, but they may indicate a trend and should be noted. Tests should include the following parameters; be sure to record the results in your tank logbook:

  • Temperature
  • Salinity
  • pH
  • Alkalinity
  • Ammonia
  • Nitrite
  • Nitrate
  • Phosphate
  • Iodine
  • Calcium

Cleaning Your Aquarium

When you decide that a major cleaning is due, take the time to go through your entire system and do it right (the more frequently you do it, the less time it will take each time). Start with the inside of the tank, and work your way through the rest of the system. Placing a couple of old towels on the floor in front of the tank during cleaning helps protect the flooring from water damage.


  1. Scrub the algae from the tank walls and submerged equipment.
  2. Siphon-clean the substrate.
  3. Change the water, as needed, and replace with new (pre-mixed) saltwater.
  4. Retest water parameters that previously were off, and add supplements to adjust levels, as needed.

Filtration system

  1. Clean debris from the bottom of the sump (a turkey baster works great for this).
  2. Change/clean the mechanical filter media.
  3. Check/clean/change the adsorbents for phosphate and nitrate.
  4. Clean the biological filter material, rinsing in saltwater to remove debris (the water you siphoned earlier works great for this).

Protein skimmer

  1. Empty the collection cup.
  2. Adjust the air and water flow, as needed.


  1. Check to make sure pumps are free of blockage and are operating with normal output.
  2. Clean filter media and check all hose connections.


  1. Clean all fixtures and bulbs.
  2. Replace old bulbs.

Salt creep

  1. Check for potential sources of salt creep.
  2. Clean affected parts to remove salt creep.

Tank exterior

  1. Wipe down the cabinet and canopy with a damp cloth.
  2. Clean the aquarium glass with an aquarium-safe glass cleaner or a damp cloth.

Scheduling Aquarium Maintenance

As part of your regular maintenance, think about whether or not you should perform these tasks more or less frequently. The amount of debris in your mechanical filter is a good indicator. When your filter media becomes clogged, contaminants will be forced around the filter material, defeating its purpose. Quite often, you can get a pretty good idea of when your filter needs attention by the amount of water that is coming from the filter outflow: if the water flow is slower than it was right after your last filter cleaning, it's probably due for a cleaning.