You’ve set up your perfect tank. You’ve decorated it, cycled it, and stocked it with a few of your favorite fish. Now, it’s time to keep the party going with regular aquarium maintenance.
But what all does that entail?
While regular aquarium maintenance is arguably the most important part of keeping fish, many new fish parents don’t fully realize what it means. It actually does not involve doing a complete tank reset every few months, removing the fish, and washing out your substrate and filters.
Aquarium maintenance should be as unobtrusive to your fish’s lives as possible. It involves a series of small tasks performed more frequently, keeping it stress-free for your fish and manageable for you!
Why Aquarium Maintenance Matters
The main reason for aquarium maintenance is that it keeps your fish happy and healthy, which should be the cardinal goal for every fish keeper. It keeps pH and minerals balanced, nitrates low, and harmful bacteria at bay.
Regular maintenance also keeps your aquarium looking nice! It is the opportunity to remove algae and detritus buildup, keep the water clear, and tend to your aquatic plants if you have them. It lets you fully enjoy the benefits of having an aquarium, like watching your fish explore and interact with each other and also hearing your guests say “Wow! Cool aquarium!”
Once you get the process down, aquarium maintenance can also be super therapeutic. Put on some chill music, grab your bucket and algae scraper, and let the satisfying vibes take over. To help you get into that flow state, I’ve put together a list of basic maintenance steps so you can find your groove!
Aquarium Maintenance
Step One: Unplug Heaters and Filters
When you do maintenance on your aquarium, you should unplug any heaters and filters. Most aquarium heaters have a minimum water level marked on their side, usually near the top. Leaving your heater on when the water is below the line is a major fire hazard. To avoid a disastrous malfunction, unplug your heater anytime you are doing aquarium maintenance!
While it’s not as dire as a dry heater, you should also unplug your filters, especially if you are using a hang-on-back. Canister filters can be left plugged in (if you aren’t working on the filter itself), but only if the water remains above the intake. If your filter runs dry, it can cause the motor to overheat and stop working.
Unplugging your equipment will extend the life of your filters and potentially prevent a fire.
Step Two: Remove Algae
Contrary to popular belief, the best way to take care of algae in a fish tank isn’t to add an algae eater—it’s to manage and remove the algae yourself. Aquarium maintenance is an important part of keeping your aquarium free of algae. In addition to the benefits of water changes (more on that in a moment), doing maintenance is the perfect time to take a sponge or scraper to the sides of your tank and remove that pesky green slime.

Some algae can be removed with a sponge, but other varieties (like green spot algae) are more difficult to get rid of. In that case, you can use a scraper designed for aquarium use. I have also found success with a fresh, clean razor blade to clean glass aquariums, although this can scratch your tank if you are not careful. Acrylic tanks require more specialized equipment.
Metal scrapers will scratch acrylic aquariums. Don’t say I didn’t warn you.
If you have algae eaters in your aquarium, I recommend leaving at least one tank wall untouched. You don’t want to remove their food source!
Step Three: The Water Change
The most important part of doing aquarium maintenance is the water change. If you don’t have time to scrape algae or prune your aquatic plants, that’s fine. Don’t skip out on water changes.
Water changes refer to the process of taking out a percentage of water (usually 20-40%), and replacing it with brand-new water that has been dechlorinated and temperature-matched.
Why are water changes important?
Water changes remove nitrates, the end product of the nitrogen cycle, which are toxic in high amounts. Without water changes (or copious amounts of live plants), nitrates will slowly build up in your tank and harm your fish. Live plants do feed off of nitrates, but so does algae. Performing regular water changes, along with managing your tank’s photo period, will help cut down on algae growth.
Regularly changing out part of the water (with a gravel vacuum) also allows you to remove excess organic material collecting on the bottom of your aquarium. Fish waste, uneaten food, and decaying plant matter break down into brown sludge known as detritus.

Some detritus is part of a healthy aquatic ecosystem and is great food for live plants. However, an excess of it can result in unwanted guests like planaria, scuds, pest snails, and harmful bacteria.
(Now is the perfect time to remove all of the algae you just scraped off!)
Water changes also replenish and balance minerals in your tank that are depleted over time. Unless your tank is perfectly balanced (which is possible to achieve with experience), you will be dealing with a build-up or depletion of minerals and an unstable pH.
Like nitrates, minerals such as calcium and magnesium don’t evaporate out. If you only replace evaporated water, the concentration of minerals in your tank will increase over time. On the other hand, tanks with lots of plants or livestock (especially shelled creatures like shrimp and snails), will experience a depletion of minerals over time. The natural biological processes in your tank will also use up carbonates, which play an important role in stabilizing pH.
Without careful management of minerals through regular aquarium maintenance, your tank may fall victim to old tank syndrome, a phenomenon in which an established (and apparently healthy) tank experiences a devastating crash in water chemistry.

Removing water during aquarium maintenance
There are several ways to remove old tank water during aquarium maintenance. If your tank is small enough, you might just scoop some water off of the top with a cup or other small container. Of course, this won’t get all of the crud off of the substrate and is horribly inefficient, but it works in a pinch.
My favorite tools for aquarium maintenance are either a) a gravel vacuum or b) an automatic water changer.
With a gravel vacuum, you drain the water into a bucket or out the window. This works best for small-to-medium aquariums. An automatic water changer (like Python or Hygger) makes water changes on larger aquariums a breeze! It hooks up to your sink faucet and uses the running tap to generate enough suction to lift water and detritus out of your tank. However, this uses a ton of extra water, so I usually just run the hose outside, drain the tank via gravity, and use the sink connection for refilling only.
[Photo of a siphon when I have one. I never stop to take photos during maintenance and I should.]
For tanks with shrimp or tiny fish, I prefer to use a gravel vacuum and a bucket so that I can rescue any little friends that get sucked into the hose.
Enjoy the following video from Aquarium Co-Op on water changes!
Step Four: Refill The Tank
The last (okay, second-to-last) step of aquarium maintenance is to refill your tank! There are two very important things to consider when refilling your tank: new water must be close to the same temperature as the water currently in the tank, and it must be dechlorinated.
Some aquarists, especially those keeping sensitive species, set out their water for a day or so to age. This stabilizes the pH and allows any gases that were trapped in the pipes to dissipate.
For most people, it is perfectly acceptable to dechlorinate some temperature-matched water and dump it in the tank, as the dechlorinator works instantly. When using my automatic water changer, I dechlorinate it as it’s going into the tank; I just make sure to dose enough to treat the tank’s total volume.
Sometimes my fish (like my super-smart Oscar, Fishy) like to play in the stream of water that pours in from the sink. Since the water is dechlorinated as soon as it enters the tank, he is unharmed.

Step Five: Plug Everything Back In
Don’t forget to plug in your heaters and filters again! I’ve lost count of the number of times I’ve stuck my hand in a tank to find the water freezing cold because I had forgotten to plug my fish’s heater back in. Sorry, guys.
Step Whenever: Filter Maintenance
Cleaning out your filter is a part of aquarium maintenance that is often overlooked. Many people switch out their carbon cartridge once a month, and that’s it. (Carbon cartridges are a scam by Big Aquarium, but that is a conversation for another time.)
Hang-on-back filters should be rinsed out with tank water every couple of months, as should any sponges or biological media. Cannister filters can go longer without maintenance, with some keepers stating they only service their filters every 6 months or so.
Regardless of how often you perform filter maintenance, your filters and media should be rinsed out with old tank water, not tap water, to preserve your good bacteria. You don’t want to risk crashing the cycle that took you so long to establish!
Frequently Asked Questions
Can I leave my fish in the tank during aquarium maintenance?
Yes! As a matter of fact, it is recommended. Catching all of the fish, moving them to a different container, and then dumping them back in is a recipe for shock. Fish are sensitive little guys, and we don’t want to subject them to further trauma.
How often should I clean my fish tank?
The frequency of aquarium maintenance depends on what kind of fish you keep, your stocking level, and if you have live plants in the tank. Some fish are highly sensitive to any level of nitrates in their water, and so water changes must be performed frequently. Tanks with a lot of fish, or just a few really messy ones, will require increased maintenance. If you have live plants, they will help keep your water chemistry in check, but water changes are often still required. Some keepers keep low-stocked, heavily planted tanks, and they are able to perform water changes very rarely.
A typical water change schedule is about 25% once a week. I recommend that people start with that and test their water weekly to monitor pH and nitrates to see what is actually required to keep their tank healthy with their stocking.
Should I use soap to clean my aquarium?
No. While Dawn’s commercials imply it is safe to clean up baby ducks, soap is toxic to fish and will kill them if they come into contact with trace amounts. It damages their gills and protective slime coats. When I’m about to stick my hands in my fish tank, I rinse my hands with water only.
Conclusion
Performing aquarium maintenance doesn’t have to be a chore. With time and experience, it will become second-nature. You may even find it satisfying!
Regular maintenance keeps your tank beautiful and your fish healthy, but the frequency of maintenance for your specific tank will depend on how heavily stocked your aquarium is.
I hope this little guide helps you on your aquarium journey.
Happy fishkeeping!


























