Water Changes & Aquarium Maintenance

Consistency is more important than perfection. Small, regular maintenance is far healthier than infrequent deep cleanings.

Why Water Changes Matter

Even in a fully cycled aquarium, waste slowly builds over time. While beneficial bacteria convert toxic ammonia into nitrate, nitrate continues to accumulate until it is removed through water changes or absorbed by live plants.

Routine water changes help:

Remove excess nitrate.
Replace essential minerals.
Remove dissolved organic waste.
Improve water clarity.
Support a healthy biological balance.
Reduce stress on your betta.

How Often Should You Change Water?

Water change frequency depends on several factors:

Aquarium size.
Number of fish.
Live plants.
Filtration.
Feeding habits.

As a general guideline:

Aquarium Size Recommended Maintenance

5 gallons 20–30% weekly

10 gallons 20–30% every 1 to 2 weeks

20+ gallons 20–30% every 2 weeks (depending on stocking and water tests)

Always use your water test results as your guide rather than following a schedule alone.

How Much Water Should Be Changed?

For routine maintenance:

20–30% is appropriate for most aquariums.

Larger water changes may be necessary if:

Ammonia or nitrite is detected.
Nitrate becomes elevated.
Medication is being removed.
Organic waste has accumulated.

Avoid replacing all of the aquarium water during normal maintenance.

Performing a Water Change

A basic water change consists of:

Turn off electrical equipment if necessary.
Use a siphon or gravel vacuum to remove water.
Clean debris from the substrate while siphoning.
Replace the removed water with dechlorinated, temperature-matched water.
Restart all equipment.
Ensure the heater and filter are operating normally.

Gravel Vacuuming

Waste naturally settles into the substrate where it continues to decompose.

During routine water changes:

Vacuum small sections of the substrate.
Remove uneaten food and fish waste.
Avoid aggressively disturbing the entire substrate at once.

Beneficial bacteria also live within the substrate, so gentle cleaning is preferred over deep cleaning.

Cleaning Decorations

Algae and biofilm naturally develop on decorations.

Most decorations only require occasional cleaning.

When cleaning:

Rinse with removed aquarium water.
Avoid soap or household cleaners.
Scrub gently with a clean aquarium brush if needed.

Some algae is completely normal and does not need to be removed immediately.

Filter Maintenance

Your filter houses the majority of your aquarium's beneficial bacteria.

To protect your biological filter:

Rinse filter media in removed aquarium water.
Never rinse biological media under untreated tap water.
Never replace all filter media at the same time.
Replace disposable media only when necessary.

A dirty filter is often healthier than a sterile filter.

Heater & Equipment Checks

Inspect equipment during every water change.
Check that:
Heater is maintaining temperature.
Filter flow remains consistent.
Airline tubing is secure.
Thermometer is accurate.
Lights operate properly.
Lid fits securely.
Early detection of equipment failures prevents emergencies.

Glass Cleaning

Algae on the glass is completely normal.

If desired:

Use an aquarium-safe algae scraper or sponge.
Clean only the viewing panels.
Leave algae on the back glass if you enjoy a more natural appearance.

Never use household glass cleaners near the aquarium.

Live Plant Maintenance

Routine water changes help:

Remove excess nitrate.
Replace essential minerals.
Remove dissolved organic waste.
Improve water clarity.
Support a healthy biological balance.
Reduce stress on your betta.

Water Testing

Routine testing allows you to identify problems before your fish is affected.

Regularly monitor:

Ammonia
Nitrite
Nitrate
pH

Additional testing for GH and KH may be useful depending on your local water supply.

Monthly Maintenance

Once each month:

Inspect airline tubing.
Check heater operation.
Inspect electrical cords.
Clean filter intake.
Remove mineral buildup.
Check decorations for damage.
Ensure plants remain healthy.

Common Maintenance Mistakes

Avoid these common errors:

Replacing all filter media.
Washing decorations with soap.
Performing unnecessary 100% water changes.
Forgetting to dechlorinate new water.
Adding water that is much colder or warmer than the aquarium.
Over-cleaning every surface.
Neglecting routine maintenance.