Black dust - could be algae - on bottom of pool

[bc21bc]

We have a 22,000 gallon, inground pool with correct chlorine and PH levels - shock every week - even use algaecide occasionally. But EVERY morning - these black, cloudy spots come back in the same places - and spread in a similar pattern. If I vacuum - they come right up - but then they just come back the next day!

[Doubled1]

Could be algae growing on the outside of liner.

[sheila]

You need to clarify, the bottle will say how long it takes to drop all the stuff down, vaccum to waste which gets it right out and shock the pool, this always works for me! good luck!

[Kaye in Illinois]

My neighbor has had a recurring problem for 5 years with gray clouds forming as you said. Now our pool has it this year. She has taken samples in to many pool supply stores and noones seems to know what it is. It seems to be floating in clouds at the bottom of the pool and can be vacumed up but disipates if you stir it. After you vacuum it clean it reappears the next day or later that day in the same places. We have shocked and clarified and vacumed to waste. With no luck, she has had a pro come out and drained her pool scrubbed the liner replaced the filter. Tonight with only about 18 inches of new water we could see it already returning on the floor of her pool. HELP! If anyone reads this and has an answer we would love some help. Ours showed up when we opened the pool this year. Her started at the end of the first year they had their pool and has never gone away. Our water tests correct for all the chemical levels. The pool places said that algae would be adhered to the liner and would not be suspended in the water in cloud like formations and be able to vacume it up. We don't know if it's algae or a fungus or if it's dangerous. We now fear we will be doomed as they are and never be able to get rid of this problem. Somewhere I read there are resistant algaes and fungi and that a chlorine/bromine combo might work.

[elaine]

I currently have an above ground pool with a vinly liner.
I have been having an ongoing problem since last year with a black algae dust that collects at the bottom on my pool and no amount of vacuuming will get rid of it. It seems that every time that I vacuum the fine black algae from the pool using the filter, the next day the pool is dirty again with the black algae. It seems that when using the vacuum I am not only dissipating the black algae and whatever I can catch with the vacuum seems to just get blown thru the filter. I have tried vacuuming to waste which seems to help but does not solve the problem completely. Any advice? Are there any type of special vacuums or chemical that can help??

[WoodyWoody]

Mine has a layer of gray dust that reappears no matter how much I filter (sand filter). I think it's some kind of precipitate like iron dust (we use high alkaline well water to fill it). The acid and chlorine levels are standard. The filter doesn't remove this black dust for some reason. It doesn't spot, it's just an even layer of this dust that looks like a gray cloud when I brush it to the drain.

[Nancylou22]

Black dust? Anyone heard of "Dirt Algae"? I've been fighting this for a year and a half, I was first told it was mustard algae. As time went on, the color has turned from a sand color to dark brown or black, even with new sand in the filter. When you brush it or vaccuum it dissappears only to come back and settle a few hours later. I had someone come out and tell me it was "Dirt Algae", very rare and comes from the dirt underneath the liner (just as weeds can grow through an above pool liner). I have never heard of this and am looking for more information. Any help out there?

[Ruzz]

May be a phosphates problem. Try PhosFree
http://www.poolcenter.com/chemicals_poo ... micals.htm

[short term fix]

I have the same thing - and have been able to get rid of it by slowly vacuuming over the "puddles" of fine black dust and bypassing the filter, evacuating it right out of the pool into the yard. You will have to refill the pool a little but it's worth it because as everyone has said, it seems to go right through the filter and back into the pool. I don't know what the stuff is, but try it, it works!

[angie]

My neighbor has had a recurring problem for 5 years with gray clouds forming as you said. Now our pool has it this year. She has taken samples in to many pool supply stores and noones seems to know what it is. It seems to be floating in clouds at the bottom of the pool and can be vacumed up but disipates if you stir it. After you vacuum it clean it reappears the next day or later that day in the same places. We have shocked and clarified and vacumed to waste. With no luck, she has had a pro come out and drained her pool scrubbed the liner replaced the filter. Tonight with only about 18 inches of new water we could see it already returning on the floor of her pool. HELP! If anyone reads this and has an answer we would love some help. Ours showed up when we opened the pool this year. Her started at the end of the first year they had their pool and has never gone away. Our water tests correct for all the chemical levels. The pool places said that algae would be adhered to the liner and would not be suspended in the water in cloud like formations and be able to vacume it up. We don't know if it's algae or a fungus or if it's dangerous. We now fear we will be doomed as they are and never be able to get rid of this problem. Somewhere I read there are resistant algaes and fungi and that a chlorine/bromine combo might work.

Did u ever find out the problem.I have the same issues and have spend thousands of dollars trying to fix this?

[floridapooltech]

That does not sound like a phosphate problem. Also, "Phosfree" is not a good choice of phosphate removers as all natural chemistry products contain even more phosphates, defeating the purpose to begin with. The best phosphate remover on the market is made by SeaKlear http://www.swimnsaveusa.com/phosphateremover.html. Have you tried cleaning out your filter and running the pump for a full day? This may help as you will need to cycle your entire pool water several times to clear out any contaminants.

[chem geek]

I don't believe that Natural Chemistry products contain phosphates. Do you have a specific product you believe does? I can show you the MSDS for its ingredients. Phosphates aren't a problem anyway if one maintains a sufficient Free Chlorine (FC) level relative to the Cyanuric Acid (CYA) level since chlorine alone can kill algae faster than it can grow regardless of phosphate (and nitrate) level.

[b]

We found out our lifeguard kids were bringing home lake algae and introducing it into our pool when they dived in after work..
Do not let anyone dive into your pool who has been in a lake or natural body of water. wash hair take a soapy shower also.
As a matter of fact we have seperate bathing suits .or you can wash your bathing suit before going in a pool with it.
Good luck/ We still battle brown algae dust anyway. I vaccumm it before we go in

[over thinking]

Black dust will most of the time be from someones roof dust that gets blown into the pool. If you had black algae it would not vacuum up nor any stains.

[bajllc]

Black dust will most of the time be from someones roof dust that gets blown into the pool. If you had black algae it would not vacuum up nor any stains.

I have the black dust in the bottom of my pool too. I use the saltwater pump system with a sand filter pump. Not too long after I vacum up the "dirt" it comes right back. What did you do for yours? I am certainly hoping it is not any kind of algae. It seems to form in the seams of the pool but brushes and vacums right up. It looks like dust when it is stirred. No clouds or water problems that I see