Old Tank Syndrome

[dabaers]

Here is a great link about a topic I found rarely mentioned when long time fish keepers suddenly have 'problems' when "everything has been fine for months/years" and they add a new fish.

Mods, feel free to move this, I couldn't find a more appropriate place.

www.bestfish.com/oldtank.html

Kath

[Allaquatica]

thanks, great subject. I am finding these are usually the tanks that decimate livebearers and other similar fish. In planted tanks that ph drop at night can be a killer when C02 rises and acidifys the water. You can find all your guppys floating at the surcface whereas other fish are fine.

Not sure if many people do this but usually once every 6 months to a year I take out everything in the tank, saving about 75% of the water and give all the filters and gravel a good clean (in old water to preserve bacteria) to remove all detritus in the tank. Seems to do the trick of overcoming this problem because it still seems to happen even if you DO your 25% water change weekly or fortnightly.