How do you clear up algae in pools?

Answer 1

Black algae is a serious problem, particularly during the summer. In the semi-private pool we had, the technician tried to fix the problem with the water in the pool. We ended up [hired a new pool company] having to empty the pool, do the remedial things to the pool surface, replace the sand filter. It was expensive and probably would have been easier to do it the hard way first.

If it is at the bottom, brush with s/s brush turn pump off and add trichlor on top of the algae, let it seat for 2-3 days, brush again. If it is in the walls add silver based liquid algaecide as per manufacturer's recommendations.

"Black Algae" (actually blue-green algae) forms in cracks and crevices on pool surfaces, especially plaster finishes. We normally find black algae growing in, but not limited to, shady areas of the pool.

Black algae is more typically found in concrete or plaster finished pools; it is very uncommon to find it in vinyl liner pools. It is known for a heavy slime layer and "skeletal growths" that make it impervious to normal chlorine levels (1.0 - 2.5 ppm). Black algae can grow "condominium style" providing layers of algae one on top of the other. Slight cracks in plaster or fiberglass walls are perfect breeding grounds for black algae especially when the pool is not properly maintained.

Two ways to get rid of black algae, algaecides typically do not work, mainly just a waste of money. First way is to spread either cal hypo or granular triclor directly on the algae. Lower Ph so the killing form of chlorine is more effective generally 7.0 to 7.4. You first should brush the spots with a ss brush. Do not do this on a dark plaster or vinyl liner pool, chlorine will either bleach or stain color. When doing this turn off pool sweep for a few days. Second and most effective way is to get two cases of liquid chlorine 8 gallons, and two gallon of ammonia hydroxide (most pool stores can order this for you) and muriatic acid. Close the pool for two weeks. Do not let anyone swim or animals drink from the pool for at least two weeks (diarrhea). Lower pH to around 7.0 Add the 8 gallons of chlorine around the pool. Turn on filter pump let run for 24 hours at least. Now you have to add the amonia hydroxide. When you do this make sure that no one hangs around the pool for a few hours (there are some gasses from the mixture of chemicals). let your system run as normal after the 24 hours. Brush pool with ss brush as often as possible. And make sure that the pool is not use. can not stress this enough. Wait till the chlorine residual has lowered to safe levels to reuse pool. At least two weeks. May have to add more chlorine after week one depends on the amount of BA, may have to try method one during this process. What this does is with the combination of ammonia and chlorine raises the residual to around 50 ppm and burns out the BA from the root. Once this is done there will or may be etching in the plaster from were the BA was, to help with this get a sanding block from your local pool store or professional, and sand the areas were the BA was to make the plaster more uniform.

I am a pool professional and have done this on a few pools and works like magic. I have done this to a pool that was covered with black algae, tried everything on this pool and nothing else worked also did the first way that i talked about, only helped a little just slowed down.

Do not scrub the pool with acid, will do nothing other than burn plaster. You can use liquid chlorine to scrub pool, this works to kill the algae and helps to bleach the plaster and disinfects the pool when a pool was not properly sanitized. Muriatic acid is not going to kill the algae, only will temporarily make the algae disappear. If you have your pool re-plastered make sure that the plasterer cuts away the spots were the algae was. I have seen pools that had Black algae before being re-plastered and soon after new plaster was applied it came back. Some times you have to remove the gunite as well.

Caution

Mixing Any type of chlorine product with amonia hydroxide is asking for a dangerous out come. Don't Do It.

Balance your pool water, brush the algae spots with a stainless steel algae brush to break the outer shell, in a vinyl liner pool use a 3M black scrubber pad. Having done this, super shock raising Free Available Chlorine to 5 to 10 ppm add a good copper or silver based algaecide, make sure the product is chelated which will prevent staining and follow the instructions to the letter. These are products that more is not better.

Answer 2

I believe this may be a question for someone in Florida. I am not familiar with this type algae however, I have heard of it before. I would superchlorinate and add Yellow Treat by United Chemical. BUT, before you react to this talk to a neighbor to see what they have done in the same situation. Second opinions are valuable.

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Answer 3

You need to reduce the light, algae will grow with more light also if the gravel is light in color that will promote algae growth the darker the better. Don't waste your time tearing the tank down the algae will be back very shortly. you can purchase algae controller but I found the best result is less light. By the way brown algae is not harmful, also make partial water changes remove the water from the bottom of the tank with a tetra hydro cleaner at least once a month if possible.

Answer 4

Do frequent water changes and buy an algae scrubber. Get a good one( usually around 10 dollars) that will collect the algae instead of simply removing it from the glass into the water.

Answer 5

cause its gross

Answer 6

in a swimming pool

Answer 7

Chemicals