Betta Care: How to Perform Water Changes

Regular water changes are the best and easiest way to keep your fish healthy and active. Try to establish an appropriate water change schedule and stick with it. A reminder on a calendar if you have multiple tanks doesn’t hurt!

Please remember that a fish tank or decorations should never be cleaned with soap or other cleansers that may be toxic to fish. Never spray the outside of your tank with Windex or other cleaners, as the chemicals may go right into the water.

A useful method for keeping all tanks clean between water changes is a clean, unused turkey baster. This is a great tool for sucking up waste, uneaten food, and any other debris off the bottom of the tank. Always be sure to rinse with hot water when finished or before using, especially in multiple tanks.

The temperature during water changes

During water changes, it is necessary to maintain a very similar, if not exact, water temperature for the clean water as what was previously in the tank. Large temperature fluctuations can be very stressful for bettas. This is important to keep in mind also if you remove your betta from the tank and place him or her in a separate container during cleaning – this water should be the same temperature.

Before cleaning your betta’s tank, it is important to have new water prepped and ready to go. If your betta lives in an unheated bowl at room temperature, leave a container of water out for a few hours or overnight so the temperature will be the same. Always remember to add a water conditioner to tap water for removal of chlorine and other harmful-to-fish elements before adding your betta to the clean tank!

If your betta lives in a heated bowl, it is still important that you obtain the same water temperature of his previous water before you replace him in the tank. If your pH and other water conditions are stable right from the tap, you can just mix the water accordingly, test with a thermometer, add a water conditioner and you should be set to add your betta back. If you need to let your water ‘age’ overnight to stabilize pH or other factors, some people heat a portion of dechorinated water in the microwave and mix it with room temperature water to achieve the necessary temperature.

1-gallon tank: For this size tank it is generally recommended to do a 100% complete water change once per week. However, the best way to establish a proper water change schedule is to monitor your water readings, especially ammonia levels. It is crucial to your betta’s health to avoid ammonia from forming in the tank. If you detect ANY ammonia, it is time for a partial or complete water change. Ideally, you will want to get to the point where you can avoid ammonia from showing up by changing the water one day prior to detecting the toxin. The ammonia level should always stay near 0 ppm.

2-gallon+ tank: For anything larger than a 1-gallon tank, such as a 2-gallon uncycled tank, you can probably go about 2 weeks before doing a complete water change with a partial water change or two in-between. Again, make sure to watch water readings to determine the best cleaning schedule for your tank. Uneaten food and waste will raise the ammonia level in some tanks faster than in others.

Less than 1-gallon tank: For a tank smaller than 1-gallon, such as a ½-gallon bowl, a complete water change is needed about every 3 days. It is especially important to test the ammonia level frequently in a tank of this small size. Partial water changes every day to every other day are definitely a good idea. If this sounds like a bit too much work, a larger tank such as a 1-gallon tank may be a better option for you. Your betta will thank you for the extra living space also!

Cycled tank: If you have a cycled tank (with a filtration system), only partial water changes will be necessary. Since you have successfully cycled the tank, you should no longer get substantial ammonia or nitrite levels, only a nitrate reading that you will want to monitor. The nitrate level should always be below 20ppm, the lower the better.

How to clean the tank (uncycled bowl or tank with no filter)

Cleaning your betta’s tank involves removing the betta from the tank and placing it in a special cleaning cup with a cover, thoroughly rinsing plants, decorations, and substrate in hot water, and wiping down the inside of the tank. Make sure to rinse everything very well and check to make sure nothing in the tank has become damaged or sharp through wear. NEVER use soap or other cleansers to clean anything that comes in contact with your betta! Hot water is the only safe way to clean your tank, substrate, decorations, etc.

There are two main ways to remove your betta from his or her tank. One way is to use a net, catch the betta gently, and then (with your hand covering the top of the net so the betta does not jump out) carefully place in a special cleaning container that already contains freshwater treated with the proper water conditioners. Make sure to immediately place a cover over the cleaning container. Once you have finished cleaning the tank, you can either pour the betta back into the tank right from the cleaning container or again scoop him out with the net and place him back into his home. If you choose to use this method, you should purchase a Brine Shrimp Net, rather than the traditional green fishnet. A brine shrimp net is made of a soft, fine mesh material that should not harm your betta’s delicate fins.

The other method for removing your betta from the tank is quick, harmless, and less stressful for your betta than using a net. For this method take a cup, such as an unused drinking glass, and wait for your betta to approach the top of the water. When the betta is near the surface, dip the cup into the water nearby the fish. This will create a vacuum that will suck both the betta and water swiftly into the cup. Quickly place a cover over the top of the cup and you are ready to clean the tank. Once you have finished, simply pour the betta and water back into the clean tank, making sure you hold your hand over the cup when you pour them out to make sure the betta does not jump. You may need a swift hand at first, but the more you practice this method the easier it gets. If necessary, you may try to entice the fish with a pellet at first, but eventually, this will become unneeded.

How to clean the tank (cycled tank with filtration system)

If you’ve successfully cycled your tank, your weekly work and upkeep become much easier, as only partial water changes will be needed. The best way to determine when to perform partial water changes (20-25%), is to monitor your nitrate level. You always want to keep this level below 20ppm, the lower you can keep it the better. Ideally, you will want to get into the habit of performing partial water changes before the nitrate reaches this level. When you perform partial water changes, it is a good idea to use a gravel vacuum to get the gunk out of the substrate.

FAQs About Water Changes for Betta Fish Tanks

As I used to be a new fishkeeper, I found myself full of questions about betta fish care. For that reason, this part is for frequently asked questions about full water changes for your betta fish tank. Please note that there are other approaches to fish tank maintenance.

What is a full water change?

Full water changes (or FWC) is exactly as it sounds. You’ll empty the tank, wash all of the parts completely and reassemble it.

What are the benefits of a full water change?

The benefit is knowing that your betta water quality is top-notch at all times. The downside, of course, will be the stress on your fish from being removed regularly from his cozy home to a cup and then back to his home.

How often are FWCs required? 

That depends. Since some fish produce more ammonia than others, you’ll need to start by testing the water daily to become acquainted with your fish’s needs.  When your water test indicates measurable ammonia (let’s say day 5), you’ll need to change the water and then change it every fourth day from then on.

What steps are required for a full water change?

1)  Unplug the heater (and filter, if you have one) and wait 15 minutes.

2)  Remove your fish with a cup (not a net).

3)  Empty your betta fish tank.

4)  Thoroughly rinse everything with hot water: tank, decorations, gravel, plants, etc.

5)  Reassemble the tank. Do not plug in the heater.

6)  Add warm water (78 – 80 degrees Fahrenheit).

7)  Add betta water conditioner.

8)  Drain the cup holding your betta (without stressing him too much) before gently adding him back in.

9)  Wait 15 minutes, then plug in your heater.

Why do I have to wait 15 minutes for the heater?

Many heaters are made of glass. To minimize the change of breakage, you should allow the heater to acclimate.

Why should I use a cup and not a net to remove my fish from his tank?

The fins of a betta splendens can catch in a net and tear easily. You bought the prettiest fish in the store.  Let’s keep him that way.

Is it really necessary to remove everything from the tank?

Ammonia is toxic to your fish. The only way to ensure that water is the cleanest it can be is to tear the tank down each time. 

Could I do a partial water change instead of a full one?

There are many reasons for choosing to do a partial water change (PWC) instead of a full one. If your busy schedule prevents you from completing a full water change, remember that you’re starting with ammonia in the tank, so you won’t be to wait as long until your next full water change.

Any last tips about full water changes?

1) If you drain the betta cup over a sink, make sure to block the drain first.  More than one pet betta has gone down the drain.

2) Set a timer to remind yourself about the heater.  It’s a little too easy to walk away from the fish tank and not plug the heater back in.