SPECIAL WATER PROBLEMS
Algae
Good water maintenance normally will keep algae under control. If the water takes on a
greenish or mustard colored cast and black or dar green spots appear on the surface finish, you
have algae.
There are two types of algae: free floating and clinging. Some of the clinging varieties may resist
all efforts and hang on as black, green or brown patches.
There are several ways to get rid of algae.
Check the total alkalinity of the pool. Have it adjusted 80-120 ppm. Adjust the pH to 7.2 to 7.4.
Then
superchlorinate
. Shut down the filter for about 24 hours. Brush the walls briskly, restart
the filter and vacuum away the dead algae. To get rid of black spots, brush the pool and turn the
pump off. When the water becomes still, carefully pour trichlorinated isocyanurate into the pool
so it covers the area. Brush again the next day. Then turn on the pump to filter out the debris.
Do not allow swimmers in the pool during this period.
Pouring liquid chlorine right on top of them can destroy persistent colonies clinging to interior
surfaces. However, only the outer layers of cells may be killed, leaving surviving cells beneath
to re-emerge when growth conditions are favourable.
Ask your pool service company for recommended Algaecides.
If algae persist, call the pool service company.
Check chlorine residual and pH after heavy chemical treatments, and do not allow swimmers in
the pool until the water is properly balanced and the chlorine is at a safe level.
Stains
A pool surface can be stained by debris, metal objects, algae and mineral deposits. Yellow or
reddish brown stains may be caused by iron in the fill water. Too much acid added to the water
at one time can cause stains. Maintain the proper pH to help prevent staining. Hairpins, toys or
other metal objects dropped into the pool should be removed immediately to prevent rust stains.
Corrosion and electrolysis.
Corrosion can result from an over acidic condition, improper use of acid chemicals, or oxidation.
Corrosion also can be caused by electrolysis. Whenever two different metals come in contact
with chemically treated water, a small electrical current flows between the metals. This current
does not give an electric shock, but it can cause corrosion of active metals such as iron and
produce rust spots on metal.
