Re: Temp and Fish

>> What evidence is there to support the theory that this water temperature is
>> bad?  I realise that disease can spread faster, but also I think that it
>> encourages plant growth.  Would anyone know if it has any influence on CO2
>> levels - I can turn my Dupla CO2 unit on very high and still not get my CO2
>> levels into the 'high' range.
>As for fish, higher temp increases their need for oxygen (due to
>faster rate of metabolism, I think) so that you need higher oxygen
>content in water. Different fishes adopt differently to that, for
>example goldfish have trouble already with moderately high temps.

Two thing are at work with goldfish. First, they're not tropicals and
require more oxygen because of their deeper bodies. Second, warmer water by
itself holds less dissolved oxygen. So when you combine the two, you get
less available oxygen and a fish whose metabolism has sped up.

High water temp isn't bad in and of itself. It's only bad if your fish or
plants do better at lower temps.

Greg. Tong
San Francisco, CA, USA
gtong at sirius_com

"Every infinity is composed of only two halves."