Watermaid ecoblend Owner's Handbook Manual page 32

At the first sign of adversity, the algae population goes into a reproduction phase to produce spores. The size
of these spores is less than 0.2 microns. D.E. filters are able to filter 5+ microns and sand filters are only able
to filter 20+ microns.
Algae will die from doses of chlorine as low as 0.05 ppm concentration, but spores can resist chlorine levels up
to 10 ppm. Domestic salt chlorinators cannot achieve such a level.
Spores, however, cannot tolerate copper salts as copper attaches to the shell or endospore preventing
germination. Hence, the most effective algaecides contain copper salts. Avoid those with the main
constituent 'benzalkonium chloride', as it destroys chlorine.
For a few black algal spots, suspending 50 grams (1.7 oz) of stabilised chlorine in a weighted nylon bag over
the trouble spots may remove them.
For a more serious algae problem, it is advisable to follow the procedure below:
Lower pH below 7, generally by the addition of up to 2 litres (4 pt) of pool acid, as this is an essential
1.
part of reducing algae resistance and dissolving the outer shell of the spores.
About 4 hours later, add a copper treatment to attain a 1 ppm copper level in the pool. An economical
2.
method is to mix about 1 heaped tablespoon of copper sulphate (approximately 70 grams or 3 oz)
dissolved in 10 litres (21 pt) of water spread around the pool. Alternatively, any copper-based
algaecide may be used.
WARNING: Do not swim in the pool for at least 24 hours, as the copper treatment may discolour
hair and clothing.
After about 12 hours, a stainless steel brush and a garden hose fitted with a brass jet gurney (available
3.
from hardware stores) can be used to remove algae from the pool walls.
Floc the pool with a clarifier. After a few hours, a blanket of debris will settle on the pool floor and
4.
can then be vacuumed directly to waste (i.e. NOT through the filter). The power to the cell should be
turned OFF while vacuuming to waste. Following this, the pool should gradually attain a clean, clear
condition after continuous filtration and chlorination.
Finally, the use of lanthanum carbonate (or "Starver") is recommended to reduce the phosphorous
5.
content to less than one part per billion. This starves algae of an essential element for growth.
Please note: If a copper-based algaecide (which may contain nitrogen compounds such as benzalkonium
chloride) or a quaternary-based algaecide is used, then a sufficient chlorine reading may be impossible to
obtain for up to four (4) weeks, as chlorine is incompatible with nitrogen compounds.
As a guide, the WATERMAID® chlorinator may need to be run non-stop for several days to overcome the
addition of an algaecide.
For spas, it is often best to drain, clean and refill. Follow the manufacturer's recommended procedure.
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