Evening star., 1935-01-19

inner walls, but most thickly on the
side that receives the most light. In
normal practice it should be per-
mitted to remain on three walls, but
kept OF the side most used for OBJ
servation purposes. Ordinarily rnls
is the inner, or room side.
Various scrapers may be used, but
q wad of absorbent cotton carefully
but firmly wiped over the inner side
Of the glass will remove 1t most sat
isfactorily. The plants should be left
on the remaining sides. 1t Is pc
culiar but natural thing that after
one has q tank with this good growth
In 1t, no tank thereafter without 1t
ever looks quite right. or even healthy
The blue-green forms, distinguished
from the former by having q blush
tone, and being Shiny in character,
are among the greatest pests in small
aquarium management.
We have never seen 4 good OF
healthy tank with 1t in 1t, and in
all cases. 1t must be gotten rid Of,
even IL the aquarium has 10 be taken
down and begun all over again.
Often this procedure is the shOrtes
method, after all. This nuisance form
Of algae Is inimical TO fish life, ss
well as to higher plant life On the
latter 1t forms q web, preventing the
plant from breathing. Perhaps it IL
not always understood that under
water plants must breathe, just the
same rs f1shes. and. just as most Of the
latter, must get their oxygen solely
from the water, In which it 10 held as
free. II covering of any sort, even
OF other plantlets, Ia over 1t, II cannot
breathe, and 50 must die
II IN question whether the blue.
green algse are any more of q menac
than the brown algse. The latter
show that the tank Is not getting
enough light. This. in turn, means
that the higher plant forms will not
grow, and. therefore. will not help
the water condition. This inimical
condition In turn reacts on the animal
life.
These brownish forms may be re-
moved by cotton, also, but unless more
light is provided they will form again
The "free-living" forms are green,
but they are distinguished from ths
good green sort by living throughout
the water. rather than on the glass.
They color the water q delicate pea
green. which becomes deeper and
deeper. in time hiding the fishes from
view. This green water" ~ it 10
called. seldom forms if the more de-
sirable sorts of green slgse get q foot
hold first. which is just another res =
son for welcoming them.
These free-living, or non Attached.
sorts. are good for the fishes. owing
10 the large amount of oxygen they
release. This benef1t, however. is out
weighed by the fact that the owner
cannot see his charges
Free-living forms are proof posi-
tive that the aquarium is getting TOO
much light, also probably 100 much
food permitted to 20 uneaten. The
remedy is to cut down on the amount
OF light. and feed rather more lightly.
Do not be discouraged II the water
does not clear up Immediately Often
it takes month. but when 1t does
clear it will remain So
Thread-aleae may catch baby
fishes, and have little to recommend
them. They are best removed by en-
tanglins them with the end of q stick
Of some sort. Green sisse which forms
on the bottom il not so bad, but we
prefer natural sand at all times.
One of the best ways sf building
up the desirable soft green slgae is
to keep q small electric bulb burning
at one end Of the tank. This win
stimulate the formation OF the good
type. in most instances, but It must
be watched for OVERRIDING, and heat
ing the water too high. Nature at
its best is a balance. and any over
doing leads TO a decline in one di-
rection or the other.