Home > Aquarium > Water Quality

Water Quality

By: Jennie Kermode - Updated: 4 Jun 2013 | comments*Discuss
Water Quality Water Chemistry Tropical

In order to keep fish successfully in your home aquarium it's important to have good quality water. Many beginner aquarists think that water is just water - it all looks the same, right? In fact, it varies a great deal. Understanding how and why will help you to keep your aquarium in much better condition.

The sensitivity of fish, plants and invertebrates to water quality varies. Some are very hardy and can cope with quite a bit of pollution, but even the most delicate fish should not sicken and die as often as they do due to poor conditions. Good quality water does require ongoing maintenance, so think about this when you set up your aquarium equipment and choose your fish. Don't buy delicate fish if you can't make an ongoing commitment to monitor, clean and generally care for their environment.

Natural Pollutants

No matter how clean the water you originally use for your fish, in time it will become polluted. This is because fish produce waste products just as humans do. These can build up in the water, making it both unpleasant and poisonous, with rising ammonia levels. The natural biochemical cycle of an established tank will break them down into less problematic compounds, but sometimes this cycle gets overloaded. If your tank is overcrowded or if you have too few plants or too much of the wrong sort of algae, the ecosystem can slip out of balance, resulting in dangerous levels of pollution. This can make your fish more vulnerable to disease and has the potential to kill them.

Natural pollutants can be effectively removed using filtration. Your tank will support more fish in healthy condition if you have a more effective filter system, but filters need to be cleaned from time to time too, so make sure you choose the right one for your aquarium's needs and for the level of maintenance you're prepared to commit to. You should also be prepared to clean the aquarium by hand every one to two weeks, scraping off algae from the sides and siphoning the gravel. The latter is especially important if you have an undergravel filter, as these suck particles of waste down through the gravel and some inevitably get stuck, building up to problematic levels over time.

Water Changes

Most aquariums benefit from regular partial water changes. You should never change all the water at once, as this will kill the beneficial bacteria which sustain your aquarium's ecosystem, and it will also put your fish at risk of shock due to changes in the water chemistry. A good basic rule is to change about a fifth of the water per week. If you have delicate fish, add new water slowly so as to reduce the risk of shock.

Learning how to look after an aquarium will make you think again about the quality of the water which comes out of your taps. You should never put fish into pure tap water, as it usually contains chlorine (and often fluoride) which, though hardier fish can sometimes survive it, will cause them a lot of pain and stress. Leaving water to stand for an hour will get rid of these chemicals but will not do anything about other pollutants, so it's best to treat the water with a commercial product designed for the purpose, such as Interpet Fresh Start or Tetra Aquasafe, before adding it to the aquarium.

What other pollutants might you expect to find in tap water? The most significant are heavy metals. This is particularly problematic if you have old plumbing with lead pipes which gradually leach lead into the water, but there are some heavy metals present in almost every water supply. Most commercial water conditioners will bind these into non-toxic molecules, keeping your fish safe.

Looking after the water in your aquarium isn't always an obvious issue as, until things start to go really wrong, problems aren't usually visible. But making the effort to provide good general maintenance and monitor water chemistry will pay off by helping you to keep happy and healthy fish.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
my fry keep dying. My angel fish fry keep dying I clean the tankand feed then 3 times a day with LIQUIFRY No1 what am i doing wrong
jolski - 4-Jun-13 @ 11:51 AM
could you tell me the hardiest tropical fish to keep ,and how many in a 50lt tank.
jolly - 1-Mar-13 @ 10:20 AM
Share Your Story, Join the Discussion or Seek Advice...
(never shown)
(never shown)
(never shown)
(never shown)
Enter word:
Latest Comments
  • Bob
    Re: Dealing with Bullying Between Fish
    Hi. Would like some advice,I am having to take out a male swordtail,as it is bulliying the other two swordtails,who are…
    10 September 2020
  • Lee
    Re: Dealing with Bullying Between Fish
    Hi, I'm hoping someone can help. My elliotti cichlids bred not long ago and I left them to raise the babies by themselves.…
    16 August 2020
  • Ruthie
    Re: Dealing with Bullying Between Fish
    Hello, I am taking care of my Dad's fish since he passed away back in January. I know how to clean the tank and such…
    3 August 2020
  • Wteach
    Re: Dealing with Bullying Between Fish
    So, I have this big blue gourami. A couple years ago he suddenly go aggressive in chasing and forcing all the other fish…
    7 July 2020
  • Jen
    Re: Dealing with Bullying Between Fish
    I’ve got 25ltr tank with 4 betta had them for months now , they were all doing fine ... omg one started to grow so big and…
    11 June 2020
  • Lynsy
    Re: Dealing with Bullying Between Fish
    I have rwo angel fish and I've just introduced another angel of similar size and its getting bullied should I buy another…
    7 June 2020
  • Evie
    Re: Dealing with Bullying Between Fish
    I have quite a large tank with only about a dozen community fish. Just recently the only penguin fish is intimidating the…
    19 October 2019
  • Frank
    Re: Flowering Aquarium Plants
    What type of nutrients can I provid from my aquarium. Help me with name of the product
    25 September 2019
  • paris
    Re: Caring for Baby Fish
    okay i was looking in my tank this morning and found little baby fish I think they were just born maybe like a day or two ago but they are…
    27 May 2019
  • Anna
    Re: Rescue Solutions
    Its rough.. I have a dominant male African Cichlid giving me alot of grief. He was in a 55 gal tank attacking everyone so everybody started hiding…
    1 April 2019