Pink Mildew

[Jason R]

I was cleaning my pool and finding what looks like pink mildew on the skimmer, my white steps, and on my white light.

What is this problem and what do I need to do? Chlorine and PH look perfect.

Thanks for the help!

[kelemvor]

Probably just pink bacteria, sometimes referred to as pink algae but I don't think it really is algae. More likely, something like Serratia marcescens. Regardless, you should be able to kill it by taking your pool up to shock levels and brushing the sides, especially affected areas and running your pump/filter continously until it's cleared (No CC detected from dusk to dawn the next day). Shock level is determined by your CYA level and the Best Guess Chart. Can you post a full set of test numbers, FC, CC, pH, CYA, TA, and CH?

[PoolDoc]

Hi Jason;

If you would, please complete the Pool Chart, linked below; doing so will give us some of the information we need to get started. 'Pink algae' or 'pink mildew' is typically a chlorine resistant biofilm. A biofilm is just a slime colony with various things growing in it. There are a lot of reports on the Internet that it's this bacterial species or that red algae -- but very few of those articles appear to have done the microscopic studies necessary to actually reach such a conclusion.

What does seem to be common to most accounts is that pink/red algae/mildew/bacteria in slime layers are
+ persistant,
+ resistant, &
+ resurgent.

In other words, you're going to have get very serious and very consistent about your pool care. For starters, you'll have to get an accurate and reliable test kit -- neither 'guess-strips' (in ANY form) nor dealer testing counts.

You need also need to read the Best Guess page linked in my signature -- unless you know what your stabilizer -- CYA -- level is, it's impossible for you to know that your "chlorine and pH" are "perfect".

Put most simply: if your chlorine and pH had been consistently perfect . . . you wouldn't have pink mildew. What you have to understand is that pool companies have NO interest in having you maintain 'perfect' levels. If you did, you'd only need or want the cheap basic chemicals and would never buy the high-margin pool goop products they love to sell.

Right now, till you get a kit and can post results, raise your chlorine to at least 2x what you've been keeping it at, and BRUSH the heck out of the spots you can see. There are other spots you can't see, but there's nothing you can do about that.

Good luck!

Ben

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+ It's much easier to answer your questions, when we have the details about your pool in one place. We often 'waste' the first few posts back and forth collecting information. So, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.

Pool Chart Entry Form

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon

[PoolDoc]

Meant to post 3 links:

http://www.ag.ndsu.edu/news/newsrele...t-is-bacteria/

The bacteria are difficult to remove completely from your home, although the stains are removed easily with a general-purpose cleanser containing chlorine bleach. You also may add ¼ cup of bleach to the toilet tank, let it sit for 15 to 20 minutes and then flush the tank a few times to remove all of the bleach. Do not leave bleach sitting in your tank because it will damage rubber valves and seals.

(that's about ~250 ppm chlorine -- you can't go that high in your pool)


http://www.myarestin.com/periodontit...-bacteria.html

Specific bacteria called red complex bacteria (RCB) are strongly associated with periodontal infection. The RCB are: P gingivalis, T denticola, and T forsythia

ooh! In your mouth!


http://en.wikipedia.org/wiki/Serratia_marcescens

S. marcescens can cause infection in several sites, including the urinary tract, respiratory tract, wounds,[3] and the eye, where it may cause conjunctivitis, keratitis, endophthalmitis, and tear duct infections.[6] It is also a rare cause of endocarditis and osteomyelitis (particularly in people who use intravenous drugs recreationally), pneumonia, and meningitis.[2][3] Most S. marcescens strains are resistant to several antibiotics because of the presence of R-factors, which are a type of plasmid that carry one or more genes that encode resistance; all are considered intrinsically resistant to ampicillin, macrolides, and first-generation cephalosporins (such as cephalexin).[2]

As Kelemvor notes, S. marcescents is an oft-suspected culprit. As you can see, it's not really benign.