Evening star., 1933-02-03
THIS AND THAT
BY CHARLES E. TRAcEWELL.

The important role which water sur
face plays in the successful keeping of
aquarium fishes In the home has long
been recognized.
Few persons, however, have worked
the matter out In actual practice to
their own satisfaction. Usually they
are satisfied with accepting the dictum
in theoretical terms.
Even the beginning aquarist knows
that the amount Of water in q given
tank is not as important as the number
OF square inches Of water surface per
fish therein.
A large number of gallons may not
keep fishes as contented and healthy
as a lesser number with more water
surface per fish
1t Is generally recognized that more
oxygen is required for the old standard
goldfish, in any Of its variations. than
for the so-called tropicals.
How many home aQuarists, however,
have gone to the trouble of keeping
records in this matter, so that they are
able to tell definitely. with some right.
just how many fish to put into a given
aquarium?
No question is asked oftenef by the
newcomer to this hobby than "how
many tropical fishes he can put in a
tank of SO many gallons"
Usually the advice he Is offered Is
Of the hemming and having variety,
so that in the end he knows no more
than he did before.
After 10 months Of investigation
along these lines, We are able to 60
the books and the magazines one
better, and announce definitely that,
according to our findings. tropical fishes
need in the neighborhood OF 10 to IL
square inches Of water surface per
animal. It Is generally conceded that
goldf1shes need about 80 square inches
per inch Of fish. exclusive of the head
and tail.
1t will be noticed that we have made
no mention Of the size Of the tropicals.
Our figures have been worked out for
what may be called average sized trop-
icals-that is. about an inch long. De-
spite the amazing difference In the
shape, construction, thickness, and so
on, Of these most interesting creatures,
they reduce amazingly well to q stand
ard, any one in tank making up in
one direction what another lacks, so
that an inch. as the average, Is about
right for the amateur, who probably
will not have very large-sized mature
fishes in his home tanks.
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actual practice. Is one inch Of goldfish
pei gallon of water, but with the square
inches of water surface as indicated
above, which is considerably more than
the average person gives these much
abused creatures. Nothing Is COM
moner than to see half q dozen of
them, and Of good size, too. attempting
to live In q tiny bowl, whose surface
presented to the air is woefully In
adequate. 1t can be done only by q
constant change Of water, which is q
great nuisance, and harmful to the
fishes. It will be noticed that we say
nothing Of artificial aeration, as but
few amateurs indulge in this. and we
believe it entirely unnecessary II the
balance" which is talked about so
much, but which, alas, is SO seldom
attained. is actually secured. whether
in a two-quart guppy jar or in a 10
or II gallon tank
Granting that the average tropical
fish. as kept in the home aquarium, is
about an inch long. exclusive Of his
tail (his head. as such. usually is not
very long, and need not be counted)
We have come to the safe and sane
conclusion, as we believe, that the
right number will be two fishes per
gallon OF water
Thus a 6-gallon tank will accom-
modate a dozen average tropical fishes
Any more Is crowding them; they may
get by, since there are exceptions tC
all rules. but the owner is taking a
chance.