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How to Easily Clean Betta Fish Tanks: An Illustrated Guide

Cynthia owns a beautiful red betta fish. She enjoys sharing fish-care tips for these wonderful pets.

How to Change the Water in a Betta Fish Tank

How to Change the Water in a Betta Fish Tank

How to Deep Clean a Betta's Tank

Betta fish seem to be a very common pet for small children and adults alike. Due to the betta's nature, the tank can be rather small and still be a wonderful habitat for them. My betta fish came to me in the form of a birthday gift a few years ago. Dubbed "Red Fishy" by my son, he has been a wonderful addition to our family. Taking on a betta should not be overly concerning as these fish are easily cared for and very resilient.

In this article, I will show you how to properly clean a fish tank in under 15 minutes. By taking the guesswork out of the fish tank cleaning process, I may just help you decide to take on a betta fish as a pet. They make a great first pet for children who need to learn the responsibility of pet ownership without taking on a larger pet like a cat or a dog.

Supplies Needed for Cleaning Your Betta Tank

Cleaning a betta fish tank is extremely easy. You will need:

  • Fresh water (allowed to sit out in open air for 24–48 hours)
  • A bottle brush
  • A bowl to hold the accessories
  • A bowl to hold your betta (covered with a breathable material)
  • Fish net or strainer (optional)

Use Room-Temperature Water

Fill a clean jug with water and allow it to sit out for 24–48 hours to off-gas harmful chemicals and to acclimate to room temperature; exposure to air removes chlorine and harmful chemicals from the water which can otherwise harm fish. Make sure the water is also at room temperature—otherwise, you may run the risk of shocking your betta fish and possibly causing the fish to die as a result.

What pH Water Levels Do Bettas Prefer?

My water comes from a well but betta fish prefer a neutral pH of 7.0 or water that is slightly acidic. With bettas, it is not a good idea to chemically alter the pH level of your fish's water. They can easily adapt to higher pH levels, as long as they are stable. If you have any concerns, you can purchase "Betta Water." I have found that for me it is an unneeded expense. You can also test the pH levels of your tap water if you have concerns about your pH levels.

Cleaning Accessories

You will need a large bowl or container for the tank accessories and rocks. You'll also want a bottle brush because they aren't abrasive and are a good choice for cleaning acrylic tanks.

Be sure to cover your Betta so that they don't try to jump out.

Be sure to cover your Betta so that they don't try to jump out.

1. Remove the Betta Fish

Before you can clean the tank, you must first remove your fish. You can purchase a small fish net to remove your fish or you can use a small, clean container like I have and scoop your fish out of the tank.

Betta fish can jump out of the water, so once you have moved them into another container, place a small card or sheet of paper over the top. This will prevent them from trying to escape.

Remove the tank accessories.

Remove the tank accessories.

2. Remove All Tank Accessories

Now that your betta is out of the tank, it is time to remove the decorative accessories that are in your tank and place them in a large bowl. They will need to be cleaned as well as the rest of the fish tank. Getting them out now makes the rest of the process easier. I have a designated plastic bowl that I use for cleaning my fish tank.

3. Remove the Dirty Water

Now that you have removed your betta and any tank accessories, slowly pour out the dirty fish tank water into your toilet or into your garden. The pebbles are fairly heavy and will stay towards the bottom, but use caution as you drain the last bit out so that your pebbles will still remain in the tank. You can use a strainer or fish net if you are nervous about losing any.

4. Remove the Pebbles

Once you have successfully drained the dirty fish tank water, you should be left with either an empty tank or a fish tank with only pebbles. If you use pebbles in your tank, pour them over into the bowl with your tank accessories.

Put the accessories and pebbles together.

Put the accessories and pebbles together.

5. Clean the Accessories

Now that your accessories and pebbles are in the same container, you can begin cleaning the accessories. The bottle brush comes in handy for cleaning accessories as it is able to reach areas you would otherwise miss. You should be able to actually feel when your tank accessories are clean (they become slightly slimy to the touch over time as they reside in the tank).

If your accessories have built up a large amount of slime, you can use a fish-safe cleaner (products like Dawn are toxic to aquatic species). Make sure that you have completely rinsed the accessories before you put them back into your tank.

Rinse away debris from the pebbles.

Rinse away debris from the pebbles.

6. Clean the Tank Rocks

Cleaning decorative accessories are slightly easier than cleaning the rocks or pebbles that lay in the bottom of the tank. Using my hands under hot running water, I rub the rocks and pebbles to loosen the slime and food remnants that cling to the rocks. Once I have loosened and run water through the pebbles, I drain the water from the bowl.

You will no doubt be able to visually see the gunk wash away as you drain the rocks. I repeat the process as long as necessary to remove food remnants and gunk that builds up. Once you are finished, drain any remaining water and set aside.

7. Clean the Tank (Acrylic)

Cleaning the acrylic fish tank is actually a breeze. You may find small shards of rock or pebble remnants. These will need to be wiped out with a towel, using caution as the acrylic is prone to scratching. This is a lesson I learned the hard way.

Once you have cleaned out any shards of the rocks, place the fish tank under running water and begin scrubbing with the bottle brush. The bottle brush works exceptionally well in this application; it will get into the corners with ease. It only takes a few moments to give the tank a good clean. If your fish tank has built up a lot of slime, you can use a small amount of fish-safe cleaner to remove it. Use caution to completely rinse it clean with multiple rinses if necessary.

8. Reassemble the Clean Tank

Now that you have cleaned the tank, accessories, and rocks, you are ready to reassemble your fish habitat. How you proceed is totally up to you. I generally add the rocks first and then add the accessories. Once I have everything placed, I slowly add the fresh water with a blend of the old to the tank. Repositioning the accessories may be necessary if they shift position when you add the water.

9. Put Your Betta Back in the Clean Tank

Congratulations! All the hard work is behind you! Now it is time to reintegrate your betta fish into his or her clean tank. As you can see from the photos above, there is a fair amount of sediment or debris in the container I put "Red Fishy" in while I cleaned his tank. It's okay if you pour this back into the freshly cleaned fish tank as you only want to change 30–50% of the tank water weekly or else you risk shocking your fish (according to You can otherwise do a deep cleaning of your tank on a monthly basis.

My Betta Fish Tank Recommendation

Betta fish tanks come in all shapes and sizes. I have been through many different fish tanks in the years we have had "Red Fishy" as a pet. I find that a larger fish tank like the one I use is actually easier to clean than some of the smaller ones I have used in the past. With a smaller tank, you will have a harder time cleaning out the corners. It is just a bit awkward to deal with a small tank.

Though Betta fish do well in shallow waters, I prefer letting my fish have ample space to swim. A larger fish tank also allows for the addition of accessories so that your fish has a place to hide if they choose.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

Question: What if my Betta doesn’t like his tank?

Answer: If you feel that your Betta does not like his tank, you may want to examine tanks specifics. It is important to note behavior changes, as it could be something unrelated to your tank that is an issue. It is important that if you're not running a tank filter, that you change the water on a frequent schedule.