Why Maintenance is Essential

An aquarium is a closed ecosystem. Unlike a lake or ocean, there is no natural water renewal. Fish waste, uneaten food, and decomposing organic matter accumulate and gradually degrade water quality.

Regular maintenance helps maintain stable water parameters, prevent diseases, limit algae growth, and provide your fish and corals with a healthy and balanced environment. The good news: with a well-established routine, maintenance only takes 30 minutes a week.

Water Changes

Water changes are the cornerstone of maintenance. They dilute accumulated pollutants (nitrates, phosphates) and replenish minerals and trace elements consumed by inhabitants.

Frequency and Volume

• Freshwater: 20 to 30% of the volume each week
• Saltwater: 10 to 15% of the volume every 2 weeks
• Heavily stocked tanks: up to 50% per week if necessary

Technique

Use a siphon to drain water while cleaning the substrate. New water should be at the same temperature (+/- 1 degree) and treated with a conditioner (freshwater) or prepared with synthetic salt and RO water (saltwater).

Cleaning the Glass and Substrate

Algae naturally accumulate on the aquarium glass. Use a cleaning magnet or scraper to remove them during each water change. For the substrate, siphoning during a water change is sufficient to remove accumulated waste.

Never clean the substrate, glass, and filter on the same day: you would eliminate too many beneficial bacteria at once.

Filter Maintenance

The filter houses the majority of your nitrifying bacteria. Its maintenance must be done with caution:

• Rinse filter media in a bucket of aquarium water (never under tap water, chlorine would kill the bacteria)
• Never replace all filter media at the same time
• Clean the impeller and propeller every 2-3 months
• Replace activated carbon monthly if you use it

Feeding

Overfeeding is the number one cause of water quality problems in aquariums. Feed your fish 1 to 2 times a day, in quantities they can consume within a maximum of 2 minutes. Anything not eaten within this time pollutes the water.

Vary the diet: flakes, pellets, frozen food (brine shrimp, daphnia, bloodworms), blanched vegetables (zucchini, spinach) for herbivores.

Regular Water Testing

Test your water regularly to detect problems before they become visible. The parameters to monitor depend on the type of aquarium:

Freshwater vs. Saltwater Maintenance

Maintenance differs significantly between these two types of aquariums:

Freshwater: simpler and more forgiving. Water changes are quick (conditioned tap water). The main focus is on algae control and plant pruning if you have a planted aquarium.

Saltwater: more demanding in terms of precision. Each water change requires preparing saltwater with RO water. Parameters (KH, Ca, Mg) must be maintained within narrow ranges. The protein skimmer requires regular cleaning of the collection cup.

Typical Maintenance Schedule

When to Call a Professional

Certain situations warrant professional intervention:

• You go on vacation and no one can take care of your tank
• You lack time for regular maintenance
• You encounter a recurring problem (algae, diseases, mortality)
• You own a complex reef aquarium with demanding corals
• You want professional maintenance for an aquarium in your business premises

FAQ

How often should I clean my aquarium?

A 20% weekly water change and glass cleaning are sufficient for most aquariums. The filter should be cleaned every 2 to 4 weeks.

Can I use tap water directly?

For a freshwater aquarium, yes, provided you use a water conditioner to neutralize chlorine. For saltwater, use only RO water.

My aquarium smells bad, what should I do?

A bad smell indicates a water quality problem: overfeeding, dead fish, clogged filter. Perform an immediate 30% water change, check your parameters, and identify the cause.