It is not necessary to add formalin each time the water is changed.
formalin is one of the best and safest general disinfectants to use.
Gelatine insolubilised by formalin (formo-gelatin) has been used for making tabloids, wound dressings, and artificial silk.
All bags and utensils should also be disinfected with this formalin solution.
This solution is variously known as formalin, formol, and formaldehyde solution.
In the museum all specimens should be removed at once from formalin to alcohol.
formalin may be used in place of alum for hardening the gelatine.
Fishes intended for skeletons should never be placed in formalin.
Of the invertebrates all, except the insects, are preserved in alcohol or formalin.
A great many types of formalin generators have been devised.
formalin for·ma·lin (fôr'mə-lĭn)
An aqueous solution of formaldehyde that is 37 percent by weight.