AROUND HOME : Notes on Spanish Colonial Furniture, IBM Selectrics, Etched Glass and Goldfish : ANIMALS : Save the Goldfish

WHEN W. C. Fields was asked why he reportedly would not drink water, he is said to have replied: “Because fish live in it.”

Pet store owners might want to keep this story in mind when they hear customers complain about the rapid deaths of goldfish they have just purchased. After a little questioning, the truth comes out, and customers invariably exclaim, “You mean you have to change the water?!”

Yes, water in a small goldfish bowl must be changed-- almost every day-- if there’s no filtering system, and the reason has to do with the way water disrupts living cells. Fresh water, by its very nature, flows into spaces that have higher concentrations of ions or molecules. This means that water is continuously invading the cells; the chemical reactions of life require high concentrations of sodium, potassium, calcium and thousands of other substances, all in just the right amounts.

Fishbowl water, if left unchecked, dilutes all these concentrations. Consequently, fish must excrete large volumes of water in the form of urine. Urine contains proteins, sugars and other goodies that bacteria crave, and so the bacteria begin to multiply.

When people purchase goldfish and don’t change the water frequently, they inevitably wake up some morning to find their goldfish floating belly up in the drink.