How to Change Water in a Fish Tank
If you are keeping tropical fish, you need to know how to change water in a fish tank and why. Perform partial water changes of 20 to 30 percent every two weeks. Frequency depends on how many fish you have and how quickly the aquarium gets dirty. Changing water reduces harmful bacteria and nitrate levels, cleans the water, keeps fish healthier, makes the tank look good and improves the quality of life for your fish.
Things You’ll Need:
- 2 Buckets
- Siphon hose
- Dechlorinator
Fill up a clean bucket with water the night before you plan to do a partial water change on the fish tank. The bucket should hold approximately the same amount of water as you plan to siphon out. Removing chlorine naturally saves the cost of dechlorinator. Chlorine evaporates from tap water in 24 hours. If you start with fresh water, just use a dechlorinator purchased from an aquarium shop to take out the chlorine.
Locate your second bucket and siphon hose and place them by the tank.
Turn off or unplug filter systems, heaters, pumps and lights. Basically, turn off anything electrical that could be dangerous while you are working in the water.
Insert the siphon hose into the tank and create suction through the hose. After inserting the hose into the tank, take the other end and suck on it to draw the water through the hose. When water begins to flow through the hose remove your mouth from it and let it drain into the empty bucket.
Use the siphon to remove water and clean the substrate (sand or gravel). Gently, push the siphon through the gravel to pull water, plant debris and fish poop up and out of the aquarium into the bucket. Periodically, check your bucket, so it does not overflow. Be careful not to suck up any fish. Do not worry if you accidentally suck up a fish. Just grab a net and net the fish out of the wastewater and put it back in the tank. Fish are usually okay.
Remove the siphon hose when your bucket is full or you have completed the water change. Empty the contents of the waste bucket outdoors in a garden or toss it into your compost pile. You can just dump it down the sink.
- Pour the dechlorinated water into the aquarium slowly, so you do not disturb your fish or uproot plants. Reconnect lights, filters, heaters and pumps that you may have disconnected prior to the water change.