INTRODUCTION 
BELDT’S AQUARIUM, INC. 
LET US GET BETTER ACQUAINTED 
Thanks to You 
In Florissant Valley twenty miles 
from dewntown St. Louis, is located 
a greenhouse much different than 
the average greenhouse. Instead of 
flowers it houses many varieties of 
tropical fishes and aquatic plants, 
also water lilies, snails and many 
other things you see listed in this 
catalogue. 
A factory for the manufacture of 
fish aquariums and many other re- 
quirements for successful aquarium 
keeping is also in operation. A sepa- 
rate unit for the manufacture of 
fish foods is part of this unique 
hobby which has grown into a busi- 
ness covering several acres of 
buildings. This is the largest estab- 
lishment of its kind in the world. 
More tropical fishes are produced 
here under glass in buildings than 
anywhere in this whole wide world. 
It all started some fifty years ago when a small boy saw some 
tadpoles wiggling around a pond in a neighborhood pasture. 
When you wrote us for this catalogue you indicated your inter- 
est in aquarium keeping. It is a fascinating hobby which may 
hold your interest for the rest of your life, or you may throw 
your aquarium into the ashpit in a short time. It all depends on 
whether you get the wrong or right start; not at all on how 
much money you may spend, but on how wisely you spend it. 
aquarium keeping 
more costly and discouraging. A good clear knowledge of the 
underlying principles of maintaining an aquarium and fish will 
enable you to enjoy the hobby to its fullest extent, and in the 
forthcoming pages we shall acquaint you with as much informa- 
tion as possible. 
: For instance, if you buy the cheapest aquarium you are wast- 
ing your money. It will ruin your good table top and become a 
nuisance instead of a relaxation andpleasure. 
We are interested all the way 
through to see thats yous seus tue 
right start and everything of the 
best money can buy, in order that 
you may enjoy your hobby and de- 
rive a lot of pleasure from aquar- 
ium keeping. An aquarium creates 
interest and is of much educational 
value to the entire family, and at 
times to the neighborhood. Many 
friends have been made in the 
aquarium hobby and you may be 
one of those who will cherish this 
friendship to your dying day. 
Never consider an aquarium a 
plaything when you set up an 
aquarium. Your educational back- 
ground should contain, besides 
arithmetic, such studies as chemis- 
try, ichthyology, biology, botany and 
a lot of horse sense. You had better 
read up on some of the principles of 
instead of learning the hard way, which is 
Thanks for the inquiry. 
Sincerely yours, 
O. C. BELDT, President. 
PRINCIPAL AQUARIUM REQUIREMENTS 
An eastern or southern exposure is best. 
An hour of direct sunlight each day is 
beneficial but not absolutely necessary. 
Plant life can be maintained with aquar- 
ium reflectors. After you have decided 
where you are going to place your aquar- 
ium’ (No. i) Don't); Mdo not place it vin a 
dark corner. Then you are ready to start 
from the bottom up. 
Put only clean aquarium sand on the 
bottom, sand that is not too coarse nor 
too fine. Clean it thoroughly or get a bag 
of Beldt’s Washed Aquarium Grit. Put 
about 1% to 2 inches of this sand on the 
bottom. (No. 2 Don’t) Do not use coarse 
gravel or a lot of small shells on the bot- 
tom; food and refuse will lodge among 
this, decay and cause plant roots to rot, 
water to foul, poisonous gases to develop 
which results in suffocation of fish life. 
OVERCROWDING 
Overcrowding the aquarium is a rather 
tough propesition to thoroughly under- 
stand. You can even put too many plants 
of a certain kind in an aquarium. Most of 
the bunch plants, such as Myriophyllum, 
Cabomba, Ludwigia, etc., which are tied in 
bunches should be taken apart and plant- 
ed in single strands. Most all of these 
bunch plants will root if you will separate 
them and plant the cut ends in the sand. 
But if you leave them tied in bunches 
they will usually rot. Too many of these 
plants may produce carbon dioxide and 
consume oxygen to survive instead of 
producing oxygen. Certain varieties of 
plants cannot overerowd the aquarium; 
for instance, Vallisneria can grow so 
thick that you may count 100 plants to 
the square foot and you could hardly 
plant it thick enough to cause any dam- 
age. 
PLANTS PRODUCE AND ALSO 
CONSUME OXYGEN 
When an aquarium receives sufficient 
light, the plants produce oxygen. At 
night plants consume oxygen. Plant life 
absorbs carbon dioxide and the refuse and 
droppings of fishlife. Plants which have 
grown and multiplied in an aquarium 
for a long period usually are beneficial 
and do not cause trouble. Only newly 
purchased plants, when freshly replanted 
and if too crowded, may be detrimental, 
so your No. 8 Don’t should be, do not 
overcrowd plants; while the No. 4 Don’t 
should be, do not overcrowd fish. 
The only important factor of crowding 
fish life in the aquarium is water surface. 
Of course, artificial aeration will solve the 
problem of supplying oxygen to the fish. 
The greater the water surface of an 
aquarium the more fish it maintains in a 
healthy condition. If you ask, “How many 
fish can I put in an aquarium?” you will 
need a dozen answers. The size of the fish 
is the most important factor. Guppies 
and Moons, about four to the gallon. Fish 
from 1% to 2 inches long, about two to 
the gallon. 
OVERFEEDING 
Overfeeding must be avoided at all 
times. Never more than one person should 
feed the fish. They seem to be hungry all 
the time. Surplus food should be siphoned 
off. Learn to feed only enough food so 
that the fish will consume all of it in 10 
minutes. If the water becomes foul and 
Page 4 
smells, it is a sure sign of decaying fish 
food. We also offer all of the principal 
live foods. Kindly check index under the 
heading of Live Foods. 
TEMPERATURE CHANGES 
An even temperature is very important. 
Great temperature changes may prove 
fatal; 75 degrees F. is a good temperature 
for the tropical aquarium. It suits al) 
varieties; some may like it a little cooler 
Never put cold fresh tap water in an 
aquarium to make up for evaporation. 
Use hot water, let it stand and cool off. 
y 
S 
When starting a new aquarium, you 
usually have only drinking water avail- 
able for this purpose. Drinking water 
usually contains a lot of chlorine, which 
is a deathly poisonous gas to fish life. It 
will linger in water even after it has 
stood for some time. The only safe way 
to start an aquarium is to use Clorout. 
When you put one tablet to a gallon of 
fresh water, it at once changes the chlo- 
rine gas into a friendly salt. We list this 
inexpensive chemical compound on page 30. 
Just the same, let the tank set at least 
one day before you plant it and another 
day before you put fish in it. So your 
Fifth Don’t should be, “Do not rush fish 
or plants into a newly setup aquarium.” ° 
