How to do a Water Change for a Freshwater Aquarium

Water changes are an incredibly important step to maintain a beautiful aquarium, but for new aquarists, the task can be daunting. If you know what all needs to get done during the water change, it isn’t hard to get it done.

1. Gather necessary materials

There are a couple of things you are going to need to perform a water change. First, you are going to need a hose with a pump for moving the water out and back into the tank.

You also need some sort of water primer. This is used to take out chlorine and other chemicals that are dangerous for fish.

Lastly, you are going to want to have some sort of aquarium brush. This is going to be used to clean the inside of the glass.

2. Prepare water for tank

At this point in the process, everybody does it differently depending on the resources available to them. Some people choose to set the temperature of the water coming out of the faucet to the correct temperature before and then fill the tank directly from the faucet, while others prefer putting the water you are going to use in a separate container (another tank, bucket, etc) and throw in a heater to fix the temperature. I use the second method. First, I fill the separate tank with enough water to replace however much I am going to take out of the tank later, then put the heater from the display tank in this tank, and wait for it to hit the desired temperature (whatever you normally keep your display tank at). Don’t forget to put the prescribed amount of water primer in the water and mix it up! I prefer using the amount that would treat the full volume of water in the display tank, as better more than you need than not enough, but that is a personal preference.

3. Drain display tank

How much water is taken out of the display tank varies from person to person, as it isn’t an exact science. I usually take between 50% and 75% of the water out. Any more than that and it gets dangerous for the fish because of the risk of the fish going into shock due to differences in the old water and new water. For this step, all you have to do is put the end of the hose with the pump inside the display tank, put the other end in a sink or anywhere you want to dispose of your water, and plug the pump in. Then just wait until you are satisfied with how much water is taken out.

4. Clean glass on inside of tank

While you are waiting for the refill water to reach a good temperature, now is a perfect time for you to clean the inside of your tank. This is where your aquarium brush comes in handy. Just wet it in the water that is left in the tank and scrub off any algae or buildup on the glass of the tank. If the rocks or other props inside the tank need cleaning, now is the time.

5. Refill tank

Now you are finally ready to refill the tank. For this step, all you need to do is put the pump inside the tank with the new water (or connect your hose the faucet), and fill the display tank. Be careful when filling if you have sand in your tank, as it is easily upset. An easy solution to this is to just put your hand loosely over the hose output or to put the output against the edge of the tank.

6. Enjoy the tank!

You’re done! Now you can enjoy your hard work and have the tank clean and safer for your fish!