A basic maintenance task for an aquarium is to change the water. But it turns out that many people who are just starting out with aquariums don’t fully understand how important it is to change the water often and don’t know how to do it right. Some of them think all they have to do is empty the tank and fill it with new water. Plus, rinse and clean all the media and filters. This is a very bad mistake that usually leads to fish getting sick and dying, as well as a lot of other problems with taking care of the aquarium.
Why is it important to change the water?
All the time, organic matter builds up in the aquarium. It is made up of animal poop, food that hasn’t been eaten, and parts of plants. It builds up in the filters and substrate, where bacteria break it down over time. The simple minerals that are released end up in the water of the aquarium, where they can be used by plants and algae.
The chemical parameters of the water will get worse as the amount of organic matter in the tank goes up. In the worst cases, this can make fish sick or cause them to be under stress for a long time, which lowers their immunity and makes them more vulnerable to pathogens. So, the goal of water changes is to lower the amount of chemical compounds that have built up in the aquarium water and make sure that the water has good chemical parameters.
How often the water in the aquarium is changed
It is suggested that you change the water often. Most of the time, once a week. But in aquariums with fewer fish, you don’t have to change the water as often. But some tanks may have a lot of fish or fish from dirty species, like goldfish, plecos that eat wood, large catfish, etc. If so, you might need to change the water more often. By keeping an eye on your tank, it’s easy to figure out how often you should change the water.
How much water do you need to change?
Most of the time, experts say to change 20–30% of the aquarium’s volume of water. If you have fish that are easy to hurt, it’s best to make smaller changes more often. Also, in smaller aquariums, you should change the water less often but more often with less water. When you change a lot of water in a small aquarium, it can really throw off the balance of life.
How to get water ready?
Many aquarists put water that needs to be changed aside for about 24 hours in buckets or other containers. During this time, the chlorine that is used to clean tap water will leave it. At the same time, the temperature of the water will go up. But it’s not always possible to save enough water for water changes in larger aquariums.
You can then use water from the tap. But don’t forget that it’s always a good idea to use products like Antychlor to get rid of chlorine or Esklarin with aloe to make tap water better. I recommend Blackclarin, which is made with peat extract, for tanks with dark water. For shrimp tanks, I recommend Shrimp Guard, which, in addition to conditioning the water, helps crustaceans shed their skin and controls their metabolism. Supreme, which combines the best parts of the first two, is another good choice. It gets rid of heavy metals and protects fish from the harsh effects of freshwater on their skin, gills, and eyes. Also, adding aloe vera speeds up the process of repairing damaged epidermis.
Also, keep in mind that water from the tap is cold. So, you shouldn’t change the water in the aquarium too often so you don’t drop the temperature by a lot.
Changing the water in an aquarium vs. other maintenance jobs
It’s a good idea to do other maintenance tasks when you change the water. Turn off the heater and filters before you start to change the water. Remove the algae and dirt from the glass. You can do this with a scrub pad or a regular dishwashing sponge. Then you can begin to drain the water. When you drain the aquarium, you can also desludge the bottom to get rid of the organic sediment that has built up there. You can use a desludger made by a professional or make one out of a cut PET bottle that you can attach to the end of the hose.
If the aquarium has a special bottom for aquatic plants, you can remove sediment by moving a small hose quickly over the bottom. This is better than traditional desludging, which can damage the bottom.
During a water change, it’s also a good time to rinse out mechanical filter sponges, prune plants, and take out any leaves that are damaged or have algae on them.
After changing the water, you can use bacteria-based products like Bacto Active and Nitri-Active on the second day. Bacteria in Bacto-Active are what break down the organic material. Bacteria that break down nitrogen use the ammonium ions that are released during this process. Other mineral compounds that dissolve in the water can be used by aquatic plants, and the extras are easy to get rid of when you change the water often.
Nitri-Active adds certain strains of bacteria that eat nitrogen and bacteria that eat nitrogen dioxide to the aquarium. It is meant to be used in both new and old tanks. If used regularly, it keeps the aquarium’s ecosystem in balance and helps it clean itself.