Evening star., 1935-07-19
. THIS AND THAT
BY CHARLES y. TRACEWELL.

which Is In no sense overcrowded cannot
take the place of this rush of air.
Gases which form as the result of a
heap o. living" will form in large
tank as well as a smaS one. They will
be more diluted, of cousse, but in time
they will become concentrated, then is
when the gasping begins.
- u 4
In the outdoor pool lack Of appetite
is not so likely to occur, both because
the ratio of water to fishes is many times
as great, but more because Nature ruffies
the surface with her winds and the
whole top of the pool is in contact with
the air and this top is very much larger
than that of even the largest tank.
The chief trouble with the outdoor
pool, If we can judge from the inquiries
which come to this desk, Is the seeming
determination of the water to go green"
at this time of the year.
This simply means that various forms
of minute green algae have increased
So answering to the stimulus of the
light, that they have colored the water
a pea soup green.
This also occurs in the aquarium II
It is given too much light and espe-
cially If the tank is overcrowded. The
latter condition neceSsitates more food
and the more food the greater the
chance that some of it will go to waste.
It is this leftover food that furnishes,
after certain transformations, the nutri-
ment of the green algae.
In pool or aquarium it is difficult
condition to correct, as most persons
know who ever have dabbled with fish
keeping.
Cutting down severely on the light,
especially sunshine, is the common
remedy such as it is.
This is more easily done with tank
than a pool, of course.
1t is comparatively simple to pull
down a blind or put screen of paper
behind the tank.
The outdoor pool is another matter.
Lily pads finally screen any pool in
which they are planted, that is one of
the best reasons for planting them.
Before they do their work, however,
the water is very likely to be deep
green, hiding the fishes from view.
What can be done about 1t?
Permanganate of potash, enough to
color the water a deep pink, IS supposed
10 ClcdT Wcll NC lldi W
fishes and plants. A tremendous dilu-
tion of copper, a million parts OF water
to one part of the metal is supposed
to achieve results One is foolish, how
ever, TO take any chances with copper.
The permanganate may be tried.
Some swear that clans will clear up
a pool, but the danger of their demise
is to be reckoned with as a dead clam
will foul the water.
Others champion tadpoleS. even SnallS.
It is questionable whether any of these
methods are sure-fire in every case.
Flushing the pool with fresh water
may or may not be helpful.
Cutting down the light for time
by erecting one of these fancy lawn
umbrellas over the pool might be tried.
although it probably would slow up the
growth of the lilies.
There is a great deal of good and
bad fortune in pool and aquarium man
agement and he who has had only the
former will have little sympathy with
the owner who has met combination
of inimical circumstances from time TO
time. There is, in truth, no sure cure
for anything and any one who thinks
he has found it should realize that he
has just found it once. in all probability,
maybe it won't work at all the next time.