Ok... two ways to do this...
Either capture some of this slime from the pool, or take a good huge scrape of the junk from the papertowels.
We're going to nutralize any clorine and sequstrant in the sampe.
Do this outside or in a well vented space...
Do this where having bleaching isn't an issue.
!! Carefull, this may foam, not expecting it to do so; however, just a heads up !!
IF scrapings, then place in an 1/8cp 3% hydrogen peroxide
IF captured... try for the least amount of pool water... add enough 3% hydrogen peroxide to double the volume.
mix well,
IF we foam... once stopped, at 3 tablespoons HP and mix, repeat until foaming stops. Both organics and Metals will react with HP and foam... something fun we used to do at the job fairs was add VERY concentrated solution of HP to a small beaker with a very tiny amount of iron or lead in the bottom, cover the small beaker with an inverted large beaker with a weight on top ... the reaction starts out VERY slowly, just a few bubbles like a soda-pop, lots of laughs from the teens, worried looks on our faces just to build the drama.... then.... WHOSH
:!: so much fun watching them jump.
but I digress...
Let sit for 1/2 hour.
Something white is more than likely an organic... algae will do this... so will your skin and hair
when exposed to high levels of HP... You may need to let this sit overnight to let things settle.
If nothing happens, then you more than likely do not have any organics... thus, more than likely not algae... more likely something metalic. More over, if the stuff stays brown then I would suspect iron or something else inorganic... I would
not suspect algea...
IF the water becomes crystal clear... I mean, really really really clear, like nothing settles out, just clear solution... then... we might try to drive the FC and the pH really high to see if the metals drop out; however, this can be a tad... well... reactive.
It must be done outside.
You must not have your face anywhere close to the container... you can not be in the possible fumes!
Double the volume of the current solution with bottled-distilled/RO water and mix (at this point your hands should be safe, just keep your nose away... just in case, once again, I'm not expecting anything too nasty - just being cautious... onething when I do it, compleatly different when someone else is doing this).... after each of the following additions mix well: add 3 tablespoons bleach. Wait 5 to 10 minutes... if nothing, add another 3 tbls bleach... place in sun... check in 1/2 hour... if no change... add 3 tbls bleach let sit in sun for as long as possible... add yet another 3 tbls bleach, let sit overnight... check. In the morning, IF it's iron something brownish should settle to the bottom... Iron and many metals will oxidize and settle out with high pH (7.8 or higher) and large amounts of an oxidizer like chlorine or HP. If you get a clear or milky gel, it should not be organic at this point - the HP should have consumed the organics, it's something metalic.
-wc
"shock" it to the iron - might even use a "generous" teaspoon of bleach. Setting the mixture in the sun to "cook" might also force the reaction, especially if it is very hot outside... direct sunlight, no shade, no sunscreen - don't care if it gets a sunburn 
W.M. brand was on sale a week or so back... picked up the last four on the shelf.
