Evening star., 1935-07-26
THIS AND THAT
BY CHARLES 4. TRACEWELL.

Hot-weather care Of aquarium fishes
is much the same rs good care at any
time OF year.
There are certain features, however,
which need to be accented. when the
air is continually hot and muggy, as 1t
has been this month.
No one need fear the effect Of thunder
on fishes, for there Is no effect, but
any one who keeps either tropical speci-
mems or goldfishes ought to pay par
ticular attention to the oxygen supply.
1t must be kept in mind that the
warmer the water the less oxygen 1t
holds. In tanks the slightest bit over
crowded the fishes often may be seen
gasping for "air."
The usual way this Is overcome Is
to change the water, but there is
right and wrong way OF doing this.
Even goldfishes do not thrive on an
indiscriminate change at too close
intervals.
80 long as the water supply is good
there is no harm in siphoning OF at
least a third of the water once week
in hot weather.
This will hold for most tropical fishes
This siphoning also takes care of
another thing to be kept in mind in
Summer, the necessity for q cleaner
bottom.
Sand soiled by too much debris Of
various sorts, including excess and un-
eaten food, Is breeding ground for
inimical tank forces. These will include
infusoria, minute animals which tend
to give the water milky or murky
character.
There is q mean between peStering
q tank and doing it good
Usually this can be found in a with.
drawal of q third of the water and its
replacement with fresh water of the
same temperature. Sameness OF tenn
perature is essential, with either gold
or tropical fishes, at any time OF year.
The habit of putting in fresh water
without regard to its temperature is not
good management.
Often as much as half OF the water
in a tank which has been going along
all right may be Withdrawn, but as q
general thing 1t is just little too much
If the practice is to be a weekly one.
One-fourth or one-third, once q week.
Is enough If done regularly this kind Of
weather. 1t will freshen up the water,
dilute inimical forces, add q little oxy-
gen, some minerals. This is the only
good way to add mineral matter.
II the amount Of oxygen is not great,
added in this way, still it is large in
comparison with the amount in water
in which the creatures live under such
circumstances.
We are dealing here with q highly
artificial proposition. No doubt this
is one of the reasons why 1t has an
irresistible appeal to certain natures.
Nothing is sure in this game of keeping
fishes You may handle them for years
yet find some new problem cropping
up overnight.
1t is with an aquarium as DR.. johnson
said about the dancing bear. Not that
it could do 1t well. but that it could do
it at all was the wonder. 1t is living
wonder, the average aquarium in which
fishes are kept on dried foods.
The wonder Is that all do not die,
even under the best of management.
When we contrast their limited swim
ming area, undersupplied with life-giv-
ing oxygen, and the piling up Of un-
wanted chemical elements as the result
of excess elimination of all types, with
the clean sweeps Of enormous size in
Nature, where winds rufle the water
and currents bring up carbon dioxide
and other heavy gases, we readily realize
that the aquarium, any aquarium, holds
life under q handicap.
1t is for this reason, above all, that