Temperature
By Yechiel Kuperman, marine biologist · 49 years keeping fishTold by Empress Matilda, Dor 70
“I have lived through three pump failures, two droughts, one flood, and a summer when somebody thought it would be helpful to put ice cubes in my lake. It was not helpful. Every change passes — but some changes pass considerably more slowly when they are the wrong temperature.”
Every fish has a temperature range that suits them. Tropical fish — like the residents of the Greenhouse — need warm, stable water, usually between 24°C and 28°C. Cold-water fish like koi and goldfish prefer cooler conditions and would find that temperature most uncomfortable.
Temperature that is wrong weakens a fish gradually. Their immune system slows down. They stop eating well. They seem fine at first — and then, suddenly, they are not. A sudden change in temperature is even more dangerous than the wrong temperature itself. Moving a fish quickly from cold water to warm water (or the other way) can cause temperature shock — which is exactly as unpleasant as it sounds.
⚠️ Never move fish directly between tanks with very different temperatures. Float the bag first, add new water gradually, let them adjust slowly.
Yechiel's Rule
Know the temperature your fish needs before you buy it. Then keep it steady.
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