How To Change the Water in your Aquarium

Proper care for your fish will depend on the right balance of water pH, nutrients and temperature. Depending on the kind of fish and filtration system you have in your aquarium, you will need to change it anywhere from once a week to every two weeks. It’s usually a mistake to simply change 100% of the water inside an aquarium because you will lose the delicate ecosystem that the tank has accumulated over time, and this can cause shocks to your fish.

  • First, determine if you already need to change the water. This requires discipline on a fish owner’s part. Change the water regularly—about every week or every other week. If you have water tests, you can test for acidity and nitrite levels. Or, you can also do a visual check to determine if your water is already murky. Smaller tanks usually require more frequent water changes than bigger tanks.
  • If your tank uses a sponge-based filter, take this out. Don’t rinse it in tap water, though.
  • Siphon off about 25% of the aquarium water into a bucket. Take half of this from the top and about half from the bottom part of the tank. If you have a gravel vacuuming system, siphon out the water by cleaning around the gravel substrate. Rinse the filter’s sponge using the water that you siphoned out. This ensures that the excess dirt is removed, but the beneficial bacteria remain.
  • Prepare water for refilling in a clean container. Mix in anti-chlorine and other vitamins or chemicals appropriate for your fish. Remember that tap water might be filled with fluoride and chlorine. Follow the instructions on the solution’s packaging. As much as possible, use drinking water for best results. If you have an aquarium thermometer, make sure that the temperatures between the new and old water are the same. For best results, the water for refilling should be left to stand for a few hours to normalize the temperature.
  • Add the new water into the tank carefully. Be sure not to disturb the gravel substrate. You can already install the filter at this point.
  • Test the water several times within an hour, to be sure that the pH and nitrite levels are within the acceptable levels.

Aquarium enthusiasts recommend changing water between 25% to 75% at a time. A 100% change should only be done in extreme circumstances. In this case, you should let the water sit for about three days before placing back your fish.

Be sure to replace water that has the same temperature as the existing water in the tank. Otherwise, extreme temperature changes will cause shocks to your fish, possibly killing them.

Try to avoid transferring your fish to different containers. They are best kept in the same environment, and with the ideal levels of oxygen, nutrients and good bacteria. Moving your fish frequently will stress or kill them.

Maintaining an aquarium is a big job that requires careful measurements and methodologies. Any hobbyist would know that you need to spend some time every week to keep your aquarium clean. This should even be more frequent if you have goldfish (which are very messy fish) and if you have a small tank.


Share this article!

Follow us!

Find more helpful articles: