Young boy wearing a blue t-shirt leaning over his fish tank to start the cleaning process

How to Clean Your Fish Tank: Step-by-Step Guide for Beginners

Regular maintenance and small water changes are unavoidable if you want to keep happy and healthy fish. It doesn’t matter how good your filter is, you have to do it.

 

Allowing your tank to get dirty will cause a buildup of harmful bacteria and create the perfect environment for disease to thrive. And dealing with diseased fish is a lot harder that cleaning your aquarium once a week.

 

And if you follow this simple step-by-step guide for fresh and saltwater aquariums, it’s an efficient straight-forward task that shouldn’t take you very long. Your fish will thank you for it!

 

Benefits of Cleaning Your Fish Tank

When I say clean your fish tank, what I’m actually saying is maintaining your tank through water changes. And these water changes help restore and maintain a balanced aquarium by physically removing and diluting harmful chemicals while replenishing vital elements.

 

It doesn’t matter if you own a fresh or saltwater aquarium, you need to do this. Here’s why:

 

You’ll Reduce Harmful Compounds

Ammonia, nitrite, and nitrate can all be harmful to you fish. During your initial Nitrogen Cycle, ammonia will turn to nitrite and nitrite will turn to nitrate, and most aquarium ecosystems lack the ideal conditions to efficiently process nitrate.

 

Nitrate isn’t harmful to your fish, unless you allow too much of it to build up. Having high levels will stress your fish, making them vulnerable to disease and promoting poor growth and color development. Performing routine water changes will help control the levels of nitrate in your tank.

 

You’ll Remove Decomposing Waste Materials

Decaying organic waste in your aquarium will release toxic nitrogenous products, phosphates, and other harmful chemicals.

 

Leading to poor water quality. In extreme cases, they can create an acidic environment, compromising the buffering capacity of your water and harmful pH swings can occur.

 

You’ll Improve Water Clarity

Routine water changes help to remove discoloration and orders. And clear water plays a vital role in reef aquariums, bad water clarity will restrict the light intensity you need for proper growth of photosynthetic corals and invertebrates.

 

You’ll Replenish Trace Elements and Essential Minerals

In the wild, there’s a consistent source of minerals, nutrients, and vitamins. However, your filter will remove these vital elements or they’ll become depleted as your inhabitants use them to grow. Water change will provide a fresh supply necessary for proper growth.

 

How to Clean Your Aquarium

Let's get into it, shall we?

 

Do I have to take everything out of my fish tank?

No, you don’t want to do this...

 

It creates extra work and a large mess you don’t have to deal with. Every surface in your aquarium will grow some beneficial bacteria, and removing your decorations may kill off some of this bacteria and reduce the quality of your filtration for a while.

 

Should I remove the Fish?

No, you don’t need to remove the fish when you perform your regular 10-15% water changes. You’re going to make more work for yourself than you need to, and is going to be extremely stressful for your fish. It could even cause physical injuries.

 

Now we've got the two common questions out of the way, let's start the step-by-step guide. Please note, some steps are split into Saltwater and Freshwater aquariums.

 

Step 1: Get Your Equipment Ready

Start by making sure you’re fully prepared and have all necessary equipment:

  • Algae pad or magnet
  • A dedicated bucket (5 gallons or bigger if needed)
  • Siphon gravel vacuum
  • Thermometer
  • Water conditioner
  • Salt mix (saltwater aquariums)
  • pH testing kit (saltwater aquariums)
  • A refractometer, hygrometer, or salinity probe (saltwater aquariums)
  • Powerhead & heater (saltwater aquariums)

Step 2: Prepare your water (Freshwater Aquariums)

You’ll want to do this a day before you clean your tank. If you’re using tap or faucet water, you’ll need to use water conditioner to remove the heavy metals, toxins and chlorine which can harm your fish.

 

Filling it up a day before and allowing it to sit allows the chlorine to evaporate and become room temperature.

 

Step 2: Prepare your water (Saltwater Aquariums)

For saltwater hobbyists, this process is takes more care. You’ll need to match three measurements - salinity, temperature, and pH.

 

To prepare your water, you’ll need RO (Reverse Osmosis) Deionized water (tap water is unsafe) and test it for TDS (Total Dissolved Solids) to make sure it is safe. Ideal reading is zero, but under 10 is acceptable.

 

Next, you’ll want to create your saltwater mix. Add the salt to the water, doing this the other way around will turn the water milky and it won’t clear.

 

Use your powerhead to keep the salt mixing and the water circulation, set the heater to 80F and let it age over night. This will let the salt fully dissolve and the water stabilize.

 

Step 3: Prepare Your Tank

If you have a water heater, you’ll need to position this so it'll stay fully submerged while you're siphoning out water. If you’re heater becomes exposed, it could crack or overheat and break. I would suggest turning your filter off as well.

 

It’s not 100% necessary, but, if your filter's intake tube is at risk of becoming exposed by lower levels of water, turning it off with stop the chance of air getting into it.

 

Step 4: Clean the Sides of Your Aquarium and the Decorations

Get your algae pad or magnet and run it along the glass, be careful to scrub as little as possible.

 

It’s best to use a dedicated algae pad or magnet, not a sponge or scrubber from your kitchen. It could contain detergent or cleaning chemicals which will harm your fish.

 

If you have an acrylic aquarium, you’ll want to make sure whatever you use won’t scratch it.

Using your algae pad, lightly scrub your decorations. If you’re really struggling, you can remove them.

 

What you don’t want to do, is remove them and use bleach or boiling water. This is going to kill your beneficial bacteria.

 

Pro Tip: Do this before removing water so you will be able to remove algae debris with the gravel siphon. This will also help prevent the algae from spreading.

Step 5: Siphon the Water and Clean the Substrate

Start by siphoning your tank’s water directly into your dedicated bucket. It’s best to buy a bucket purely for this purpose as residue from soaps or detergents can be harmful to your fish.

 

Whilst you’re siphoning the water out, you’ll want to carefully go through the gravel to remove as much of the waste as possible. If you use sand, don’t use the vacuum like a shovel. Only use the hose part and hold it under and inch from the surface to suck up any waste. This will stop you from disturbing the sand.

 

If you’ve got very small fish, and you’re worried about sucking them up, you can use a never-worn stocking on the end of your siphon. Just make sure the mesh is large enough to let debris enter.

 

Siphon your water until 10-15% of your tank’s water has been removed into your bucket.

 

Pro Tip: Siphoning at and angle will prevent clogging as it allows the substrate to slide back out.

Step 6: Rinse Your Filter Media

You’re not replacing your filter media. Doing that for a routine clean and water change would remove too much bacteria and upset the water chemistry in your tank, shocking your fish.

 

You’re just giving it a rinse if it’s excessively dirty.

 

And this is where your dedicated bucket of tank water comes in handy. Rinse them with the water in the bucket, NOT tap water. Chlorine in the tap water will kill the beneficial bacteria living in your filter and you’ll have to start a new Nitrogen Cycle.

 

Pro Tip: Rinsing your filter media does not mean you never have to change it. It’s recommended you change it monthly, and when you do, include the new media with your existing one. Then remove the old one after a couple of weeks, giving the new one time to colonize with bacteria.

Step 7: Add Your New Water (Freshwater Aquariums)

Use a thermometer to confirm that the temperature is within the correct range for your tank. A dramatic change in water temperature can kill your fish. If you’re happy, carefully start refilling your aquarium.

 

Don’t forget that your fish need some space between the water and top of the tank, so they have enough oxygen and carbon dioxide exchange to breathe.

 

Step 7: Add Your New Water (Saltwater Aquariums)

For saltwater tanks, test your water using your refractometer, hydrometer, or salinity probe, the ideal reading is between 1.020 and 1.025.

 

Use your thermometer to check the temperature is in the correct range. When these levels are good, test the pH. If all the levels are correct, carefully add your water.

 

Pro Tip: If you’re struggling to lift your bucket up to your tanks edge, consider buying a quality pump. You’ll want a pump that can push water at least 5 feet high using 10 feet of flexible tubing.

Step 8: Cleaning the outside of Your Aquarium

Not essential, but it can make view your tank mates a lot more pleasurable. Only clean the outside of your tank with solutions which are designated as aquarium-safe. The ammonia fumes from standard cleaners can harm your fish.

 

On That Note...

Regular water changes is one of the most important aspects of maintaining a healthy environment for your fish to thrive. And it’s not very difficult, just follow the simple steps provided.

Christopher Adams

Hey there, my name is Christopher and I'm the creator and editor of this site. I've owned successful aquariums for the past 23 years. My mission is to educate, inform, and entertain on everything that's fish.

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