Do Water Changes Kill Fish?
Friday November 13, 2009
Water changes are touted by some, and bashed by others. One common story used when debating the perils of frequent water changes is that they will kill the fish.Is it true? Actually there is some truth to the story, but before you give up on water changes, learn the real reason why in some cases water changes do kill fish.
Photo © Shirlie L Sharpe
Comments
As this article is aimed at beginners, I think that the following should have been recommended:
1. 5% water changes are useless. You may as well not bother. A conservative water change of 20% is useful when you don’t want to subject fish to too much of a pH shift.
2. If there are any nitrates or ammonia, a 50% water change is pretty much essential. Another 50% water change a few days later will do much less to stress the fish than soaking for 48 hours in poisonous chemicals like ammonia would hurt them.
3. If there’s one thing that people who don’t do water changes should do, it’s get dip strips that read out major water quality parameters. Once a week test your water, and then do your water change percentages accordingly. You can test before and after, once or twice, and know exactly how much you’ve shifted the pH, GH, KH, and how much you’ve lowered nitrates and if there are any nitrites present, all in one handy dip-strip.
Warren
Warren,
Your comments are good, however I think you misuderstood the article. My instructions aren’t aimed at newly set up tanks that have rising levels of ammonia and/or nitrite.
I was specifically addressing situations in which a tank as been let go for a long period of time. In those cases, larger water changes can subject the fish to osmotic stress (that isn’t such an issue in a new tank or well maintained tank).
I totally agree that people don’t test their aquarium water enough. I’ve seen plenty of negative comments about the strip tests, but I think they are far more likely to be used than the more cumbersome tube tests.