Black Tar - NOT Black Algae

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

Black Tar - NOT Black Algae

Postby Appmagic » Sun 05 Sep, 2010 22:44

I have an above ground pool and use a Hayward creepy crawler to clean the bottom. I have to clean the feet & body with Goof-Off twice a month. It really seems like tar and there is no evidence on my liner.

Swimming Pool Superstar
Swimming Pool Superstar
Posts: 307
Joined: Wed 17 Feb, 2010 22:47
My Pool: License # CPO34-283076
Location: Tampa Bay, FL

Black Tar - NOT Black Algae

Postby floridapooltech » Mon 06 Sep, 2010 01:16

Appmagic wrote:I have an above ground pool and use a Hayward creepy crawler to clean the bottom. I have to clean the feet & body with Goof-Off twice a month. It really seems like tar and there is no evidence on my liner.

Is the fill water your using City, or from a well?

Black Tar - NOT Black Algae

Postby skieks » Wed 22 Jun, 2011 19:42

I have the same black goo problem in my pool skimmer. My chemicals are in balance and i have a good chlorine reading. I'm still reading other posts and doing research to discover it's origin. However, I've found that using Mr. Clean Sponges or a comporable generic brand takes the black goo off the skimmer housing and any other plastics very nicely. I just tear off a section of sponge, wipe and discard. i don't try and rinse and resuse the sponge.
15 year pool vet...

Yellow, then black oily scum.

Postby 15 year pool vet... » Tue 03 Jul, 2012 17:37

The yellow, then black oily scum develops in the skimmer ONLY if you have agitation, that is, the return jets are facing outward pushing on the surface of the water. Pool installers recommend both facing downward and opposite at about 45 degree angle. This does eliminate the yellow oily accumulation in the skimmer box, but new solutions bring new problems, i.e. the majority of flies, bees and other pool loving insects will end up on the bottom of your pool rather than being trapped in the skimmer tub. I split the difference, one angled downward, the other pushing off the surface, I only have one skimmer to clean and it's not the one I place my tablets of chlorine. I used bacquacil for years at over 1200/season... always had pink algae, (pink cottage cheese on the walls) so I switched to chlorine. Not sure exactly what this yellow/black scum is, but I too would like to hear what would eliminate it?
15 year pool vet

Yellow, then black scum...

Postby 15 year pool vet » Tue 03 Jul, 2012 17:44

One more thing, I can't believe it's body oil or sunscreens, etc... it forms even while I'm gone for up to two weeks with no one in the pool... for me it depends on the jet position, read above post. Thanks and good luck!!

Black Tar - NOT Black Algae

Postby inthe1way » Wed 22 Aug, 2012 13:07

When closing my pool for the 2009 season, I noticed some black on the bottom of my pool in the place where I always put the water hoses for my well water to add water to my pool. When I opened up for the 2010 season, the black was still there. Everytime I added the amount of water from the low line of my skimmer basket to the full line, I've to add Muratic Acid in order to lower the Alkalinity. I noticed that when I did this, it would get rid of the black on the bottom of the pool, but it would come back. I tested it, and it wasn't in the same spot. The pool store said that I could tell if it was Black Algae by putting shock in a sock and using the scrub brush on the end of my pole, apply the sock directly to the black. If the shock gets rid of it (without having to scrub it, but only apply the shock gently) then it was Black Algael If it did not do this, then it was not Black Algae. It was not Black Algae. I started putting the water hoses in the pool at different places. The black was not consistant with the location of the water hoses, probably because I stopped putting the water hoses all the way in the pool so that they were laying on the bottom. I just put them in deep enough so that the water is coming out below the surface of the water. At the beginning of the 2012 season, I had a mishap and left the Muratic Acid sit for 2 hours in the pool instead of 1 hour. It lowered my Alkalinity even more. The pool store said this was fine, because Alkalinity could be between 30-120. As long as I keep my alkalinity low (30-40) the black on the bottom of the pool stays gone. But this 2012 season I've had a worse problem. This black gooey
surface line is in my skimmer basket (it also has a tinge of brownish orange-sandy looking dirt color mixed in). I've tried the Pool First Aid numerous times, and it gets rid of most of it, but then it comes back. I called Natural Chemistry and they said it is definitely organics. They said my alkalinity MUST be 80-120 and anything less can do severe damage to the pool over time. They also said that the brownish orange tinge is iron. I have had to add the Metal Free for the iron in my pool in seasons past, but I don't think that I added any this year. They said organics can come in through the air, rain, or my well water. The organics are trapping the metal "stain" and making it so it is gooey with the black. They said get my alkalnity 80-120, and PH 7.4. Then, according to the directions on the back of the bottle, use Pool Purge. Then 48 hours later, shock. Then 24 hours later use Pool First Aid and Metal Free. Then 24 hours later use Pool Perfect and use the Pool Perfect on a weekly basis, as well as be on a weekly maintenance instead of bi-weekly maintenance by shocking and adding the maintenance amount of Pool Perfect. I will let you know if this works. I am beginning it now by working on getting Alkalinity up again first.
phosfree user

Black Tar - NOT Black Algae

Postby phosfree user » Wed 05 Sep, 2012 19:12

i found a secondary use for pool perfect + phosfree - pour a little on a paper towel and run it over the tar - wait 10 sec - repeat but this time you can wipe off the tar with the paper towel

Black Tar - NOT Black Algae

Postby an » Tue 04 Dec, 2012 21:30

My concrete cholorinated pool is approx 35 years old, never had a black goo problem until we re-routed the pipework into the pool & capped off the old copper pipework and installed new white pvc pipe. We have been unable to remove our vinyl pool cover as yet this season (which is a first) and the tempreture is in the 30's.
After running the pump for only one week after the new pipe had been installed the black tar like goo has appeared in the skimmer box. The water has been kept fairly low so only a small amount of vinyl cover is in contact with the water so I believe I can discount the cover being the issue. The pool chemicals are in balance so I am led to point the finger at the new pvc pipe. I read the earlier comment regarding plastizing of vinyl/pvc? and at this stage I am inclined to believe that is the case. Still researching tho'.

Black Tar - NOT Black Algae

Postby jelder » Wed 21 May, 2014 06:44

keep web searching, I found this info below- might help

Vinyl Plasticisers
Vinyl manufacturers use various plasticisers in the formulation of vinyl for swimming pools. These plasticisers act to keep the vinyl flexible and stable in a swimming pool. Sometimes, over the winter, unknown factors will cause an accumulation of this plasticiser on the surface of a vinyl liner. This accumulation of plasticiser appears as a "sticky liner" which, if touched, can cause sticky feet and hands and even leave "footprints" on the vinyl liner itself. Usually this material is relatively colourless and will not be evident until touched or brushed. When the vinyl is brushed, the brush will pick up dirt and other contaminants along with the plasticisers. This acts to colour the material a light yellow to darker brown colour which accumulates on the brush. This is a nuisance but also a natural occurrence that does not reflect a lack of quality or integrity of the liner. Vinyl plasticiser problems usually occur only the first or second season after opening a pool with a new liner. Fortunately, treatment of the problem is simple. Over a period of one to two weeks, as the water heats up, normal circulation of balanced pool water will alleviate the problem. Brushing is not necessary or desirable since it will only act to foul the cleaning brushes.

Quat-humate is an interaction of quats (quaternary ammonium complexes present in most algaecide products) with a class of substances called humates. Humates result from the decomposition of organic matter in leaves, grasses and soils. This matter can accumulate on the top of a cover or may just leach through a mesh cover. Usually this humate material, if present, will combine with the first application of an algaecide, such as Back-Up, and form a dark brown to black goo ring around the pool. Sometimes the goo will extend below the waterline, but most of the accumulation is at the waterline. The problem can be minimised by not allowing any portion of the water on top of the cover to enter the pool during the opening. Usually this water contains humates, in addition to other materials which can generate an initial chlorine demand or create stains later. Although this problem is typically an appearance nuisance, it is actually a desirable occurrence, as the Back-Up is acting to remove these unwanted organics, which may cause further problems later, from the water. Removal of the quat-humate substance is accomplished by brushing with BioGuard Surface Cleaner which can help dissolve this oily substance allowing the filtration system to remove it.

Chlorinator Goo
A third type of material can accumulate in automatic chlorinators. Most pools contain small amounts of oils and greases which can include natural body oils and suntan lotions. Suntan lotions can contain various carboxylates (a class of compounds) such as stearates and other organics. Carboxylates are the same materials which some manufacturers use to help bind chlorine tablets and sticks. Bio-Lab chlorine products contain no binders or stearates and therefore do not contribute to this "organic load." These organics can build up in swimming pools and eventually enter the chlorinator. Normally, the flow through the chlorinator does not allow the accumulation of these organics in the chlorinator but in periods when the system is not in operation, the organics present in the chlorinator are exposed to high concentrations of chlorine and low pH. These factors act to oxidise these organics into a yellow or beige, slightly sticky material. As the level of water rises and falls in the chlorinator, this material is deposited on the walls of the chlorinator unit. The oxidised material also can sink to the bottom and clog piping. This process of deposition is slow and usually occurs over a period of months or years. People may open the chlorinator, see this accumulation, and blame Bio-Lab chlorine tablets or sticks for this goo, when, in fact, most of the problem is contributed by bather load and the introduction of foreign organics to the pool.

This problem can also occur even though there is no apparent bather load because this is a slowly accumulating material. Any bather load in the past can contribute to a present problem. The key to this problem is prevention. Regular shocking of the pool with Burn Out oxidises some organics before they enter the filter and chlorination system. Enforcement of pre-swim showers helps wash tanning and other lotions from the body before entering the pool. Since most of the oils present in the pool are on the surface of the water, a tennis ball, large piece of Styrofoam or a "scum ball" placed in the skimmer will help catch the oils before they enter the chlorinator and cause problems. The absorbent material can be washed or thrown away after use. Presently, no safe chemical cleaning procedure has been devised for correction of the problem after it has occurred. Physical scraping of the material out of the chlorinator may help but if the cause is not corrected, the problem will recur.

Pool Scum
The fourth type of goo material in the swimming pool cannot be characterised in any particular group. Since a swimming pool is an open body of water, it is subject to contamination from the air, trees, pollution and even intentional vandalism. Many different environmental factors can contribute to a pool ring or scum. In most cases, these problems can be minimized by proper water balancing, regular super chlorination, and enforcement of shower rules. As was stated before, absorbent materials placed in the skimmer can also act to catch foreign organics and oils before they cause a problem. Since some scum lines are oily in nature, the alkaline BioGuard Surface Cleaner should be used to help remove these accumulations. Off The Wall® Surface Cleaner has also been shown to be effective in removing many of these unsightly rings and scum.

Black Tar - NOT Black Algae

Postby joycenfl » Fri 18 Jul, 2014 12:57

I also have the black tar like substance in my skimmer, my pool is brand new and for 2 months the black stuff builds in the skimmer and its hard to get off, I also use magic sponge to get it off, my pool is balanced and the water is crystal clear but the build up is awful, I use baquacil. and only there products, please help.

Return to “Pool Algae & Green Pool Water”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests