10 GOLDFISH VARIETIES AND 
for about two weeks, this being particularly true of imported goldfishes. 
They may already be inoculated with diseases only in process of incu- 
bation, but which will nevertheless develop. 
Chemical Depletion of Water. Constant absorption of minerals 
from the water by plants and fishes makes a condition which should be 
provided for. This can be done by the occasional addition of salts. Make 
a mixture of three parts of evaporated sea salt (Turk’s Island Salt), and 
one part Epsom salts. About once in two or three weeks a level teaspoon- 
full to 20 gallons of water will prove beneficial. Usually the fishes will 
greedily swallow these salts as they sink to the bottom, which acts as a 
mild cathartic with them. ; 
The decomposition of plants, etc., sets up an acid condition in the 
aquarium, which is not good for the fish and which causes most of the 
crumbling noticed on the shells of snails. Ten drops of lime water to the 
gallon of aquarium water will neutralize any ordinary acid condition, but 
a better method is to keep a small piece of Plaster of Paris in the aquarium. 
In dissolving, it neutralizes the acid, but as it only dissolves under acid 
conditions, there is no danger of getting the water too alkaline. If the 
Plaster of Paris dissolves quickly it is a sign of pronounced acid condi- 
tion. We would call two weeks a short time in which to dissolve a piece 
half the size of a shellbark in a 20-gallon aquarium. Pieces of gypsum 
will perform the same function, but more slowly. 
Pieces of coral, sea-shells, etc., look out of place in a fresh-water 
aquarium, and many of them are sufficiently rough to injure the fishes if 
they chance to be knocked against them. 
A Word to Beginners. It is much the better plan to start with a few 
fishes of the hardier varieties until the rudiments of aquarium keeping are 
well understood. If one can keep common goldfishes in perfect health 
and experience practically no losses, then it is time to branch out into the 
more varied and interesting breeds. Some beginners, having more enthu- 
siasm than experience, lose valuable fishes at the start and turn away in 
disgust from a fancy that, if properly understood, would have afforded 
them many hours of pleasant recreation. 
Aeration. In Nature there is always 
sufficient plants or air surface to keep the fish 
well supplied with oxygen, but in the aqua- 
rium, particularly on dark days when the 
plants give off little oxygen, it is impossible 
to keep the fish from coming to the surface 
without the help of some artificial means. 
This is best accomplished by means of com- 
Fic. 1. Air Pump pressed air liberated at the bottom of the 
