How To Clean the Water of Your Aquarium

Renew Freshwater Aquariums with Partial Water Change

Photo of aquarium supplies

To maintain a high quality water for your fish, it is important to renew it partially on a regular basis. Learn how to do this the right way with the minor risk to your fish and plants, keeping your water clean and beautiful.

  1. Verify if renewing water is really necessary by checking the smell and color. The first step is checking if the water is really unhealthy. If the smell is fishy (I mean really fishy -- remeber the aquarium water has a natural smell) and the color is not clean and it looks cloudy and heavy, checking the filters will be necessary. Don't forget to make a partial water change following the next steps.
  2. Take the water out. You can do that using a small bucket carefully, so you will not injure your fish or cause any damage to your decorations and other stuff. If you have a hose and syphon, of course the result will be better.
  3. How much water must I take? There is no exactly measure that can be used in every aquarium, so it is something that you have to determine by yourself. In most cases, renewing 1/3 of the water volume per week is fine and safe. But sometimes there is an accident -- the water gets too cloudy, the filter is broken, your children feed the fish too much -- and then you should change higher amounts of the water.
  4. Start cleaning the bottom of the aquarium. If you clean your aquarium and renew its water, but in a few days it looks cloudy and heavy again, maybe you are feeding your fish too much, or you need to do a bottom cleaning in the tank. It is a very simple thing. All you will need is a special hose for aquarium cleaning (you can purchase this in almost every aqua store) that suctions the bottom, taking the dirt off and keeping everything in place.
  5. Check out the filters. Cleaning the aquarium is also an opportunity to check the filters out. You can renew the filtering materials and carbon. If you use filters that need a refill from the manufacturer, there are always instructions about how long it can be used, reminding you of the time to get a new refill to your filter. The same is true for carbon and ammonia level controllers.

    If you do not use refill models, some more experience is required. You have to notice if the dirt can be cleaned (with water) or not. Exchanging filtering materials every 2 weeks is okay in most cases, but you have to consider the specifics of your tank, remembering about feeding, population, plants etc.

  6. Clean the walls. Using a sponge for aquarium-cleaning, you can take the dirt out of the walls. The water is important, but in spite of it, cleaning the walls will make your work brighter.
  7. Preparing the new water. The water you will use in your aquarium must be drinking water, with the minimum amount of chlorine as possible. It is strongly recommended that you use some kind of water conditioner to make the water acceptable to fish and plants. The PH level must be close to the one in your aquarium. For this kind of verification, you can use PH tests that can be bought in Pet Shops and Aqua stores. If the level is not close to your aquarium's, you may use correctors for PH level. Remember that the ideal PH to your tank depends on what species of fish you have, and that a different Ph level in the new water can be used to correct PH levels from acid to alkaline (recommended only for experienced aquarists!).
  8. Complete the water volume of the aquarium. Put the new water in the aquarium carefully, being helped by the bucket and hose (you need to determine what will help you more in each case).


Share this article!

Follow us!

Find more helpful articles:



Regarding Step #7, if you used distilled water from the grocery store you can eliminate the use of chemicals. I tend to buy 5 gallons a month ($0.99 ea) and just keep them under the stand, makes life simple.

By Stephen Sandecki