Skip to main content
  1. Home
  2. Other animals
  3. Evergreens

How to change aquarium water without making a mess

Add as a preferred source on Google

You’ve become a proud aquarist — it’s a wonderful feeling to say the least. But just as with all pet ownership, you need to make sure you’re maintaining a good environment for your animals. If you had a hamster, you’d have to clean his cage, a cat and you’d be changing the litter. For your fish, you need to refresh the water periodically. But doing so too often will hurt your tank’s ecosystem and cause even more problems. If you want to maintain a good habitat and keep your hands relatively unsoiled, follow these steps for keeping your fish water clean. 

Man cleans fish tank with a sponge
Varavin88 / Shutterstock

How often to change aquarium water

First things first: Don’t overdo it on the cleaning. It’s just as bad to change the water too much as not enough. About every week, you should do a partial water change, meaning getting out 10% or so. While you’re at it, vacuum or stir up the gravel to get the most out of your tank recycle. Remember that your filtration system actually does a lot of the work in keeping your tank hospitable to your favorite underwater creatures. It needs to get cleaned occasionally, too, so you should update, replace, and scrub that periodically as well.

Recommended Videos

While you won’t do a full tank clean frequently, every so often it will become necessary. When you first set up your aquarium, you’ll watch it go through the nitrogen cycle. This can give it a cloudy look for a few days or weeks, but then your ecosystem will settle into a sustaining level of all the various chemicals needed to keep the tank going. If at all possible, you should try to get away with partial water changes only, but sometimes you need to take the plunge and completely replace all the water.

How to change aquarium water

OK, but what if you really need to clean out your tank? About once per year, you’ll do a full tank cleaning, and sometimes it will become necessary to do it in between as well. Some problems can’t be cured by a partial water change or the filter, and you have to jump in (figuratively) to save the fish. When that happens, here’s what you should do.

Fish swim in a clean aquarium
Image used with permission by copyright holder

One of the best ways to track your tank is to mind your fish. Overfeeding and under-filtering frequently cause issues in aquariums since they allow too much waste to pile up, mostly in the form of extra food or extra poop. But don’t just rely on them as indicators. You need to test your water weekly to ensure it has the right balance. And look for obvious signs of problems like cloudy water and algae blooms.

Remove everything

You’ll have a much easier time of it if you have a backup tank ready to take your fish while you clean the main one. If this is just a routine cleaning, you can preserve some of the water in your backup aquarium with the fish. Make sure you bring the new water to temperature and take care of chlorine or other harmful additives. Get out the toys, plastic plants, and other accessories for a deep cleaning, too. 

Clean surfaces

Everything will require a thorough scrubbing during this process. Disassemble filters and follow directions for washing, as each model is different and you don’t want to break anything. The rest of your tank just needs a little elbow grease. Use only fish-safe cleansers and let everything dry a long time so chemical smells dissipate. 

Clean accessories

Everything in your fish house needs a good refresh, which includes all the gravel and any decorations. Some of these are even dishwasher safe, though you’ll run them without soap. As with the aquarium itself, you need to keep any tough chemicals away and stick with milder products. Leave these to dry along with the tank. 

Replace water

You can start with the water your fish are in currently — from your backup tank or wherever else you’re holding them. Then, finish the rest with brand-new water that has been treated and left to sit, usually overnight. If you can get away with changing only out 50%, so much the better. Certain issues like some parasites require starting from scratch again, though. 

You can do a few additional things to keep the mess down. Set aside a cleaning area such as the bathroom or the kitchen and put out towels while you scrub away. Use gloves and sponges so you don’t get slimed too much. Monitor the tank carefully once you put it all back together and test the water frequently for the first couple of weeks. Depending on how much water you took out, you might see the new-tank cloudiness again. If you find your water looks dirty a lot, consider upgrading your filtration system, especially if you recently added new fish. Then, the filter’s cleaning your aquarium, so you don’t have to. 

Rebekkah Adams
Former Contributor
Rebekkah’s been a writer and editor for more than 10 years, both in print and digital. In addition to writing about pets…
How to reduce nitrates in your aquarium quickly and effectively
Get the nitrates under control for your fish
Clown fish swimming through corals in an aquarium

It’s one more thing to add to the seemingly endless aquarium checklist, but you need to stay on top of your nitrate levels. You’ll never get them to zero (though if you do, let us in on the secret), but keeping the aquarium chemicals in balance will greatly increase your fish’s life span. While not quite as dangerous as ammonia, out-of-control nitrates can kill fish. Proper testing, cleaning, and filtering will enable you to reduce nitrates and keep your fish healthy. Keep reading for more tips on how to reduce nitrates in aquariums.

Read more
How to help a bird with a broken wing
Do these 4 things right away if you find an injured bird
Vet examines a falcon's wing

It’s hard to know when to get involved in the natural order of things, and many times, you’ll want to leave Mother Earth alone and let the ecosystem balance itself. But occasionally, the opportunity to step in and make a difference really does come along. If ever you stumble on an injured bird with a broken wing, you may be able to save them without harming nature in the process.

Before you ponder how to help a poor flyer, make sure the bird is actually hurt. Some animals fake injury to lead you away from a nest. If you’re certain the avian needs help, it’s time to spring into action. Here's how to help a bird with a broken wing.

Read more
The 7 most intelligent birds you can keep as pets
These species can all learn to talk or sing to keep you company
Blue macaw looking quizzically into the camera

Birds are actually one of the most intelligent creatures and have the unique skill of mimicking the human voice. Of course, most of this is just repeating back things they've heard, but they can also learn basic commands and even understand some concepts.

If you're looking for the smartest birds, you will probably want to stick with members of the parrot family. Although many other species are quite smart, like ravens, they don't all make good pets. By choosing from this list, you can bring home a bird to play with that's friendly to humans and intelligent.
What is the smartest bird?

Read more