How to Properly Clean Your Fish Tank


How to Properly Clean Your Fish Tank

People often picture a tank with algae and crusty fish when they hear you keep them. But with just a few easy steps, you can keep your aquarium looking like a beautiful work of art. Keep reading to learn our top tips on cleaning fish tanks like a professional.


Before You Get Started…

We often get asked a lot of questions from beginners. Let’s start with the most frequently answered:

How often do fish tanks need to be cleaned?

Some people say that once a week is enough, while others say that once a year. The real answer is that it totally depends! It all depends on the size of your aquarium, how many fish are kept, and the amount of biological filtration (e.g. beneficial bacteria and live plant) that you have. Fortunately, we have a free guide to help you figure out exactly what frequency is right for your aquarium.

Are you able to take the fish out from the tank for cleaning?

No, go ahead and leave your fish in the aquarium. You won’t be completely draining the aquarium, so there will be plenty of water left for them to swim in. The process of catching them can be more stressful than the slow cleaning.

There’s no need to catch the fish before cleaning an aquarium because it will only cause undue stress.

How long should water be left to cool before you add fish?

This old-fashioned piece of advice is based on the fact that chlorine can be found in tap water. However, if the water sits for 24 hours the chlorine will evaporate. Chloramine, a stable form of chlorine, is used in tap water. It does not evaporate over time. Instead, you need to dose water conditioner to make the water safe for fish, and then you can immediately use the dechlorinated water for your aquarium with no wait time.

What cleaning supplies do you need to get?

If this is your first aquarium, you may need to collect some tank maintenance materials, such as:

Aquarium water test kit – Bucket for holding dirty tank water – Algae scraper (for glass or acrylic) – Algae scraper blade attachment (for glass or acrylic) – Toothbrush for cleaning algae off decor or plants – Scissors for pruning plants – Dechlorinator (also known as water conditioner) Glass cleaner – Towel for wiping up water spills – Glass-cleaning cloth or paper towel – Aquarium siphon (also known as a gravel vacuum)

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How to Clean Your Aquarium

Now that we’ve cleared up some confusion about tank maintenance, here is a step-by-step guide for you to follow on a regular basis:

Step 1: Test the Water Quality

If your aquarium is newly established and has not been cycled yet, you need to test the water to determine if it has 0 ppm ammonia, 0 ppm nitrites, and less than 40 ppm nitrates. (For more info, find out how to cycle your aquarium.) Fish can become sick if they are exposed to higher levels of these compounds.

If your aquarium is already cycled, then the goal is to keep nitrate levels below 40 ppm. To determine the amount of water that should be removed from your aquarium and to determine if you need to take any other steps (based on our guide to water changes), use a water test kit.

A water test kit helps you determine if there are toxic levels of nitrogen waste compounds in the aquarium.

Step 2: Remove Algae

To keep your fish’s eyes open, use an algae scraper to clean the tank walls. If you have the blade attachment, it should be very easy to slice through any tough algae spots. Be careful not to catch substrate under the algae scraper or you could scratch the acrylic or glass.

You can wash the lid off if algae has formed. You should not use soap as it can cause damage to your fish. Finally, if algae covers your aquarium decor, rocks, or plants, try using a clean toothbrush to gently brush it off, either over the sink or in the aquarium. More tips can be found in our article How to Get Rid of Algae.

Keep algae under control by regularly removing it and balancing the lighting and nutrient levels in your aquarium.

Step 3: Prune your plants

If you keep live aquarium plants, take this time to remove any dead leaves and trim down overgrown foliage. You can propagate tall stem plants by cutting off a few inches from the tops. Then, replant them in the substrate. You can remove the runners from dwarf sagittaria or vallisneria plants that are spreading to unwelcome areas and move them. Finally, if the floating plants cover the entire surface of the water, you can remove 30% to 50% to ensure that the fish and plants below have enough light.

Pruning helps plants to focus on delivering nutrients to the healthiest leaves, and it also allows light to reach leaves at the bottom of the stems.

Step 4: Turn off the equipment

Before removing any water, make sure to turn off or unplug all equipment. Aquarium heaters and filters are not meant to operate without water and therefore can become damaged when running in dry air.

Step 5: Vacuum the Substrate

Take out your nifty aquarium siphon and vacuum approximately one-third of the substrate. As debris can collect under decorations and hardscape, it is important to remove them as soon as possible. The siphon is used to remove fish waste, uneaten food, leaves, and other debris from the gravel or the sand. Additionally, it can also be used to drain old tank water as well as excess nitrates. You can find detailed instructions for how to start a gravel vacuum and how to stop it if you have accidentally taken in a small fish.

Siphons are one of the most useful tools for easily changing water without having to use a cup or pitcher.

Step 6: Clean the filter

At least once a month, you should clean the filter. Many beginners think of filters like a black hole where fish poop and detritus magically disappear from the water. Filters are actually more like trash cans. However, at the end, it is still your responsibility to empty the trash can. In the same way, filters collect fish waste, but you must still regularly clean it to remove all the gunk before the filter gets clogged up or overflows.

The easiest way to maintain a corner box, canister or hang-on-back filter is to simply wash it in a bucket of tank water. You should not use soap. Use only water. If you have a sponge filter, remove the foam portion and wring it multiple times in the bucket of old tank water. You can read our last section on sponge filters for more information.

Step 7: Refill the water

At this point, you can finally refill the tank with fresh, clean water that matches the temperature of the existing aquarium water. Human hands are able to detect temperatures within one or two degrees, so just adjust the faucet until the tap water feels like it has the same amount of warmth. You can empty the bucket of tank water, which can be used for indoor and outdoor plants, and then refill it with water. You can either add dechlorinator into the bucket (dosed based on the bucket’s volume) or directly into the tank (dosed based on the aquarium’s volume). You can also add liquid fertilizer or root tabs to the substrate.

If you’re worried about messing up your aquascape or substrate, pour the new water into the aquarium through a colander or onto another solid surface (like your hand or a plastic bag) to lessen any disturbances.

Step 8: Turn on Equipment

Despite all the effort you put into cleaning the tank, the water is likely to look even worse because of all the particulate that has built up. Not to worry – turn on the heater and filter again, and within an hour or so, the debris will settle down or get sucked up by the filter.

Step 9: Wipe the Glass

For that extra, crystal-clear finish, wipe down the outside walls of the tank with aquarium-safe glass and acrylic cleaner to remove any water spots and smudges. Also, clean off the dust that has collected on the lid, light, and aquarium stand. Now you have a truly Instagram-worthy aquarium ready to wow your friends and family!

Get pleasure from the fruits and vegetables of your labor by spending hours gazing at your healthy, happy fish.