Algacide issue

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
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Algacide issue

Postby funkybandit » Mon 19 Jan, 2009 06:04

Hi All,

Our pool has blackspot algae, so we were advised to put algaecide in it (copper based), the pool was not green or discoloured to begin with only had little spots in places...we made sure the Ph was in range 7.2 -7.9 for the product, added it yesterday and scrubbed the pool as directed. Today the water is cloudy and the PH is high...we cleaned out the chlorinator cell, we dumped water that we vacuumed, added water clarifier and hydrochloric acid to bring the Ph down and added water back in as it was too low for the skimmer box after we dumped water. Pool is about 60,000 litres, concrete, salt water chlorinated.

Pool is still cloudy, is this because of the hydrochloric acid?

What should we do from here and how long if any guesses are out there till the pool is usable again? (im in australia and its boiling hot).

Any Advice appreciated


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Postby lonestar » Wed 28 Jan, 2009 11:29

Black algae is a terror. It is not easily gotten rid of. Black algae only accumulates from contuous low FC. It can also be a circulation problem that allows the FC in certain spots of the pool to be low all the time.

Did you have your water checked at the pool store? Is your salt level in line? What about your CYA?

If your CYA is not too high, shocking the pool with some stabilized chlorine might help. If the pool is white plaster, Trichlor granules are the best thing to kill that stuff. NOTE: shocking may stain the pool as youve already added copper.
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Postby chem geek » Wed 28 Jan, 2009 20:59

I agree with lonestar's excellent advice and would also add that frequent brushing is key. You have to knock off the surface layers of the black algae to let concentrated chlorine kill deeper layers and this process needs to be repeated frequently. For plaster pools, brushing and then rubbing a Trichlor puck over the area can be helpful. Just note that if you leave a Trichlor puck on a plaster surface, its acidity will likely leave a mark -- like a mini-acid-wash in the local area.

Sustained high chlorine levels with frequent brushing will eventually get rid of the black algae.

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