NEWS104
34
ardwater - softwater
So where do these terms actually come
from? After all, in the final analysis a
bellyflop causes the same amount of grief
regardlessofwhethertheswimmingpool is
full of hard or soft water! The terms "hard"
and "soft" for water were invented in
conjunctionwith theuseof soap. If a lot of
soapwas requiredtocreatea latherandthe
lather was made of small bubbles and
"hard", then the water was described as
hard, but if the soap lathered quickly and
the lather was creamy and soft, then the
water was soft. This remains of great
practical importance to thepresent day, as
H
Malawi cichlids (this is
Pseudotropheus
sp.“Daktari”) dobetter inmedium-hard tohardwater. All photos:FrankSchäfer
Water hardness is one of the most important chemical parameters in the
aquarium. Because water hardness is also of great importance outside the
aquariumhobby,everyoneought tobeawareofhow itaffectsus.
That’shardness foryou!
byHeikoBlessin
much more washing powder or soap is
required inhardwater than in soft inorder
to achieve a cleansing effect. Whether or
not you have hard or soft water flowing
fromthetapcanbereadilyseen inthehand
basin. If, with regular hand-washing using
soap, a dull deposit rapidly forms on the
surface of the washbasin, then you have
hard water, but if the washbasin remains
smooth and shiny all day, even if you are
foreverwashing,thenyouhave softwater.
Thecausesofhardwater
The drinking water that flows from our
mains is usually groundwater, though it is
sometimes also treatedwater from a large
bodyofsurfacewatersuchasa riveror lake.
Thusdrinkingwater isconstantly incontact
with earth and rock; and earth and rock
contain components that are soluble in
water, including calcium and magnesium
compounds. And they are what causes
Water chemistry
