Green Algae coming back week after week...

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

Green Algae coming back week after week...

Postby Marklora » Sun 23 Aug, 2009 19:09

Thanks chem geek. The CYA was checked by Leslie Pools. I will get a kit and test the CYA to get the exact level. Will bleach fade my liner and how should I put in Directly into pool or Ssimmer. How much every two days for 27,000 gallons. Thanks


chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Green Algae coming back week after week...

Postby chem geek » Mon 24 Aug, 2009 00:27

You should add most concentrated chemicals slowly over a return flow with the pump running at the deep end. For extra safety in a vinyl pool, lightly brush the side and bottom of the pool where you add the chemicals. Any chlorine can damage the liner -- a Trichlor puck settling to the bottom; undissolved Cal-Hypo sitting on the bottom; or chlorinating liquid or bleach poured too quickly not over a return since it is denser than water until fully mixed. When added safely, there is no harm to the liner.
Marklora

Green Algae coming back week after week...

Postby Marklora » Mon 24 Aug, 2009 06:16

How much should I add? Thanks
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Green Algae coming back week after week...

Postby chem geek » Mon 24 Aug, 2009 07:13

You can use The Pool Calculator for calculating dosages. In 27,000 gallons, to add 2 ppm FC would be 112 fluid ounces (14 cups) of 6% bleach or 55 fluid ounces (almost 7 cups) of 12.5% chlorinating liquid. This assumes a chlorine usage/consumption of 1 ppm FC per day. This is probably on the high side if you have a pool cover. If you don't have a pool cover, then your daily chlorine usage could be more like 2 ppm FC or if in very direct sunlight even 3 ppm FC though usually people raise their CYA level if they have a lot of intense direct sunlight (e.g. Arizona or southern Florida).

If you can find a pool store that sells chlorinating liquid and reuses the bottles, then that is obviously better for the environment than recycling. My local pool store charges a small deposit and I return the bottles (and plastic container that holds 4 gallon jugs) for exchange -- at the end of the season I get most of my deposit back as I then just get 1 gallon at a time for the winter.

As for safety at higher FC levels, an FC that is 10% of the CYA level is technically equivalent in active chlorine (hypochlorous acid) concentration as 0.1 ppm FC with no CYA so is very safe. Just don't drink cups of water every day (the EPA limit for drinking water is 4 ppm FC, but that assumes drinking 6-8 cups of water every day). The chlorine bound to CYA is unlikely to have any skin absorption since CYA itself has virtually none (see here ).

Another option you can consider is using 50 ppm Borates in the pool as this is a mild algicide that could take the edge off of algae growth and act as temporary insurance if you let the chlorine level get too low. You can read more about that here .
PinchMePenny

Green Algae coming back week after week...

Postby PinchMePenny » Mon 16 Sep, 2013 14:41

Clean and or Change your filter

Return to “Pool Algae & Green Pool Water”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 7 guests