How to Properly Clean Your Fish Tank

Most people imagine an algae-covered tank in which there is no way to see fish swimming inside. But with just a few easy steps, you can keep your aquarium looking like a beautiful work of art. We will be sharing our top tips to clean your fish tank like an expert.

Before you get started…

Beginners often ask us a number of frequently-asked questions. Let’s begin with those:

How often are you required to clean a fish aquarium?

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

Do you take the fish out of the tank when 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. Also, the process of catching them is more stressful for the fish than slowly cleaning around them.

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

How long do you let water sit before putting fish in?

This old-fashioned tip comes from the fact municipalities frequently add chlorine to tap water. The chlorine is toxic to fish and can cause death. However, if you leave the water out for 24hrs the chlorine will evaporate. The stable chlorine form chloramine is still used in tap water. It doesn’t evaporate. 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 products do you need?

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: Check 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.) These waste compounds can pose a danger to fish if they reach high levels.

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 (using 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: Eliminate Algae

Use an algae scraper to scrub your tank walls. This will allow you to see the fish clearly. If you have the blade attachment, it should be very easy to slice through any tough algae spots. Just make sure not to catch any substrate underneath the algae scraper, or you may end up scratching the glass or acrylic.

If algae has grown on the lid, you can easily rinse it off in the sink. 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. Read our article on how to get rid of algae for more tips and tricks.

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

Step 3: Prune the plants

If you keep live aquarium plants, take this time to remove any dead leaves and trim down overgrown foliage. To propagate tall stem plants, cut a few inches off their tops and place them back into the substrate. If dwarf sagittaria and vallisneria are spreading into unattractive areas, you can pull out the runners and move them to another area. Lastly, if floating plants have completely covered the entire water surface, remove about 30% to 50% of them so that the plants below get enough light and the fish get enough oxygen.

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

Turn off and unplug any equipment before removing water. Aquarium heaters and filters are not meant to operate without water and therefore can become damaged when running in dry air.

Step 5: Vacuum your Substrat

Take out your nifty aquarium siphon and vacuum approximately one-third of the substrate. You can move any decorations and hardscapes as necessary, as debris tends to accumulate underneath them. The siphon does two things: it removes fish waste, uneaten meals, and any hardscape. It also removes old tanks water and excess nutrients. Check out our gravel vacuum article for detailed instructions on how to start a siphon (and how to stop it if you accidentally suck up a small fish).

Siphons make it easy to change water from one cup to another.

Step 6 – Clean the Filter

You should clean your filter at least once per month. Filters are often viewed as a black hole in which fish poop and other debris magically disappear. In reality, filters are more like trash cans that collect waste, but at the end of the day, someone is still responsible for taking out the trash can. Filters can also be used to collect fish waste. But, it is important that you clean the filter regularly in order to get rid of any gunk or buildup.

The easiest way to maintain a corner box, corner, or hang-on-back filter is to simply wash it in a bucket of tank water. Again, don’t use soap. Just water. If your sponge filter has foam, take it out and rinse with old tank water. You can read our last section on sponge filters for more information.

Step 7 – Fill up the water

At this point, you can finally refill the tank with fresh, clean water that matches the temperature of the existing aquarium water. Temperatures can be sensed by human hands. Adjust the faucet to ensure that the water is the same temperature. The bucket can then be emptied of any old tank water and refilled with tap 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). This is also a chance to 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 the Equipment

Although you just spent all this time cleaning the tank, it probably looks dirtier than ever with all that particulate clouding up the water. 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!

Enjoy the fruits of your labor and spend hours looking at your happy, healthy fish.