Black Algae...HELP please

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

Black Algae...HELP please

Postby jshell » Sun 31 Jul, 2005 18:41

I have an inground pool with liner. Last year before closing the pool we discovered that we have black algae. After spending over $300 on chemicals to try and solve the problem we ended up closing the pool wiht a boat load of stuff in it and prayed when spring came it would be all right and the alge would be gone.

We opened the pool and it was still present although much lighter. Since opening the pool I have had nothing but trouble with this black algae. It now is spreading. My pool company insists that if i shock the pool with Sun-burn and then put in algacide, with a little scrubbing it should go away.

Okay, I have done this twice. So on my third try i read somewhere if you lay the "chemical" right on the black algae it will go away. I put the SUN-burn shock stuff in a white sock and placed it on each algae area and low and behold after about five minutes it was nearly gone....completely gone in two areas and very faint in the largest area. I spent almost 2-hours doing, I get up the next morning - 12 hours later - and there's the black algae again.....still present and almost as dark.

HELP....what should I do. I am at my wits end and the pool company is no help.
ANY Suggestions would be most appreciated. ( and according to the water sample test this is truly black algae and not a metal deposit of some sort)

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Postby sheila » Wed 10 Aug, 2005 13:03

Hi I had a BLACK pool in may with TONS of leaves, my husband drained to waste the entire thing vaccumed up the rest and power washed it like crazy. sucked it up with the shop vac again. When we filled it was a light green still had some algae we had to shock it to death to kill it all. 8 bags of the strongest shock everyday till clear, she said level had to be over 10 consistantly. Before I found someone at the pool store to tell me the truth, I spent over $200 in products and hours and hours, when to clean and kill it I spent about $50. to maintain it I use 2x a week shock algaecide and claflier, vaccum 2x too. I skip or slack and some green comes right back. She said it would work with Black algae just use more. good luck!! SHEILA

Black algea

Postby Peter » Sun 26 Feb, 2006 09:41

I had black algea problems in my pool for years. The swimming pool is surrounded by trees and ends up in the shade half the day. The pool also gets full of leaves. The result: black algea every time.

I drained the pool and acid washed the marcite. I filled the pool and installed a Nature2. The pool became easier to maintain but still got black algea every couple of months. I removed the Nature2 and tried the Pool wizard. It has been 3 years since the last black algea problem and sometimes it seems like a dream that I used to spent so much time, energy and $$s on my pool.

So my advice for black algea problems: Pool wizard, a little chlorine and lots of swimming and lazing around the poolside.

Black Algae

Postby cdufkat » Sat 17 Jun, 2006 16:04

Reply to Peter. What is pool wizard.? I have an inground pool that was just re-plastered 3 months ago. 3 weeks ago I saw little dots all over sections of the walls and bottom. I don't know if it's black algae or stains. How can you tell? I have to keep adding acid because my PH keeps going too high. Other than that, the pool is clear. I scrubbed quite a few times. Sometimes it comes right off, sometimes it's very stubborn. I wonder if I have some of each, STAINS & BLACK ALGAE.

Black Algae...HELP please

Postby Sandy » Fri 03 Apr, 2009 18:20

I googled to find out how to get rid of the black algae I have in my inground pool. I will try Peter's suggestion,I have tried everything short of replastering. I hope I can purchase the 'pool wizard' at Leslies Pool supplies.I will keep all posted on the results.Wish me luck.

Sandy Modesto,CA.

Black Algae...HELP please

Postby Guest » Wed 24 Jun, 2009 08:07

We were told to dump 4 gallons of shock at a time in the skimmer and let the pump run overnight. Don't let anyone swim and see it in the morning. If not clear dump 4 more gallons
Julie Plumlee

Black Algae...HELP please

Postby Julie Plumlee » Mon 31 Aug, 2009 19:52

Is it ok to swim in pool with black algae?
brad s
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Black Algae...HELP please

Postby brad s » Tue 01 Sep, 2009 08:32

You have algea in the pool becasue of one reason, not enough chlorine. You need to know the level of stabalizer (cyanuric acid) you have in the pool to figure out how much chlorine to add. The CYA level dicates how effective your chlorine is. If you use pucks, i guarantee you your CYA level is very high. A CYA level of 100 ppm would mean that you need to add at least 25-30 ppm. You need to bring the chlorine up to that level and HOLD it there until you lose no chlorine overnight. Shocking is not a one time thing. It can take a week or more. You need to get some test numbers ssuch as

Free chlorine
combined chlorine
Total alkalinity

Any algea problem (mostly) can be taken care of by adding the proper ampount pof chlorine. If you CYA level is high, which i suspect it is, your FC level to PREVENT algea would be around 8-13 ppm ALL THE TIME.

Black Algae...HELP please

Postby sanniebk » Sun 11 Mar, 2012 16:54

i have something that has turned my whole bottom of the liner black. last summer i had the pool people to sell me a lot of stuff to clean it up but it is still there. it wont even scrub off help--the water is crystal clear but the bottom and sides is black help

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