How Do I Kill White Molds and Pink Slime?

[smullins34]

Sorry, I should have given you more info about the pool. It is 36,000 gallons, underground, vinyl. Our liner is on its last legs. Barely hanging on in some spots. It is already fairly bleached out around the waterline. I honestly don't know how old it is, but suspect it is original to the pool - built in 2003 - as nothing else had been replaced when we moved in.

We've been trying to keep the FC close to 30 with liquid bleach. Although, we haven't been on it 24/7 and it has probably been around 15ish most of the time. Tonight before we added more I tested it at 25.5 with CC at 1.

[waterbear]

30 ppm FC at 80 ppmCYA just ain't gonna cut it!

[smullins34]

I was going by a table on trouble free pools. Where should we aim?

[waterbear]

I was going by a table on trouble free pools.

And there we have it!

Where should we aim?

I did already answer that before!

If you have a vinyl pool it gets trickier and requires a bit more work so as not to bleach the liner. You would need to turn off the SWCG and use a sodium bromide product and then shock to bring the chlorine up to about 10-12 ppm (bromine to about 22-27 ppm) since bromine is not stabilized by CYA this takes your 80 ppm CYA out of the equation and give you a higher activity for killing the biofilm and less likelyhood of bleaching out the liner (but some bleaching will still probably happen). You would need to keep the SWCG off and keep shocking for about a week or so of adding the sodium bromide until you have killed all the biofilms and see you are not losing sanitizer quickly during the day. Since inorganic bromine cannot be stabilized for loss from UV light the sun will quickly deplete your iso you will need to shock again to 'reactivate' the bromine. Once you find that your santizer levels are holding after the biofilms are gone it means that the bromine pool has converted back into a chlorine pool and you can turn the SWCG back on.

[PoolDoc]

Here are some 100% sodium bromide products from Amazon:

Nava Chemicals 652072097 Yellow Algae Remover, 2-Pound Bottle @ Amazon
Tropi Clear TC-4402-1 2-Pound Yellow Eliminator @ Amazon

Let me extend what Waterbear told you, a bit. Well, a lot. (Sorry!)

1. "Watermold" is a detached biofilm. Basically, a biofilm is a complex community of bacteria and other things (often, algae) that builds a slime (polysaccharide) 'fortress' which it can live inside of. When conditions are good (low chlorine; high nutrients) it will venture out, and grow. When they are bad, it just 'hunkers down' and waits. These films actually have a quasi-intelligence, with very elaborate signaling processes that tell all the different occupants how to work together. One of the last classes my son had before he graduated 2 years ago with a biochem degree, spent a lot of time on this signaling. It's a apparently an area of very active interest and research.

2. Chlorine does not penetrate biofilms well. It will oxidize them (burn them up), but it's an outside-in process, and nothing happens to the organisms till the chlorine 'breaks the walls down' completely. It takes VERY high levels of active chlorine to burn through and kill everything. But, if you don't eradicate the source, one little bit of slime can restart the process.

3. Apparently, the particular group of organisms that cause 'water mold' either are rare combo, or else they have a hard time getting started. I say this because, even though 'water mold' is VERY hard to eradicate, we don't encounter it all that often. (Fortunately!)

4. There are 4 tactics used to attack biofilms: (1) raising the "active halogen level", (2) adding detergents to the water that help penetrate and separate the slime, (3) using biocides that can penetrate the slime, and (4) physically disrupting the slime. Each one of these options has undesirable side effects.

• You can raise the active halogen level, by raising the chlorine level. But, if your pool is stabilized, you have to raise the level very high indeed. So one technique, that Waterbear described involves adding sodium bromide. Chlorine (even stabilized chlorine) converts bromide to bromine, so if you add 10 ppm of bromide (more or less) to a pool with 20 ppm of stabilized chlorine, you'll end up with something like 10 ppm of FREE ACTIVE bromine + 10 ppm stabilized chlorine. (NOTE: these are NOT the actual numbers, which are more complicated than I've indicated.) The downside is that the bromide will stick around AFTER the water mold is gone, leaving you with this large unstabilized residual. As a result, your chlorine use will be MUCH higher on sunny days, and this will continue for quite a while. But as long as you use only sodium bromide, and no BCDMH (bromine tablets) your pool will eventually return to chlorine only.
  
• You can use detergents or soapy algaecides. United Chemicals, who has been selling pool owners bromides in various forms for years (and who pioneered this method of bromide treatment, at least on a national level) have always added various phosphate detergents to their products. In the short term, this helps. In the long term, you have added phosphate algae fertilizer to your pool. Another way to do it, is to use the foamy linear quat algicides that are commonly sold. The PoolBrand algicide sold by Sams Club is a high concentration product at a very good price. We normally do NOT recommend these products, but in your case, it's an option. These products have at least 3 problems: (a) at high concentrations, like you will need, they make your pool look like a suds bath, (b) they aren't very compatible with chlorine (but this does mean you can get rid of them by shocking and filtering), and (c) at high concentrations are irritating.
  
• You can use a microbiocide that penetrates biofilms effectively. The only one I know of is monochloramine, which is created by adding ammonia to your pool, while the pH is high. It's quite effective, but it's nasty to swim in, and requires repeated shocks to get rid of.
  
• Physically disrupting the biofilm means . . . brushing, and lots of it. It also means removing your light (which you've done) and so on. The down side is just that it's hard time consuming work.

Roughly, you have two options. You can use bromide principally, without disrupting your pool use at all, but with some long term effects in chlorine use and stability. Or, you can use monochloramine & algaecide, and lose the use of your pool for probably a week, followed by maybe a week of clean-up, but once you're done, your're done.

(There may be one more option: a new manufacturer is want to give away samples of product that may be designed for your sitation. He's looking at your post, and we're looking at his product.)


Meanwhile, here's what I would recommend:

1. Fill our the pool chart so we can calculate doses for you, and such.

Pool Chart Entry Form
Pool Chart Results

2. If you aren't doing so, begin filtering 24/7 -- AND turn off your SWCG. You'll wear it out, in these conditions.
3. Establish a 60 ppm borax residual. This will help with several things, but will also make it harder for the water mold to survive. And, except for cost, it has NO downside. You'll need about 25 boxes of borax + about 7 gallons of muriatic acid to do this. (~$120, maybe)
4. Expose everything you can to the water.
5. Make sure that there's no trichlor in the skimmers, but once you've done so, add the bleach THROUGH the skimmers, so it also goes through the filter.
6. Get some water mold, and put it, and some pool water in a clear glass (wine glass). Add a tablespoon of bleach, and make SURE that the bleach eliminates it. (I want to eliminate the possibility of your problem being some OTHER kind of weird event.)
7. Think about what you'd prefer: no disruption, but long term effects, or a disrupted pool, but fewer long term effects.
8. Wait for Chem Geek's post and Waterbear's reaction.

KEYS: water mold, white mold, white water mold, white slime, pink slime

[waterbear]

I am skeptical of any new product that does not have documented studies that show it's effectiveness because I have seen LOTS of "snake oil" products but I do have an open mind and if you want to give it a try they are offering it for free. At best it will work quickly with no side effects, at worse you will still have the mold and have to try one of the other tactics. FWIW, I have used my own personal pool as a test pool on more than one occasion. Usually I have been disappointed but there has been one notable exception and that was adding borate.

In any case your pool will be out of commission for a week or more while you get the water in shape. I will tell you this. If it were my pool I would add the borate (already have it in my pool, BTW) and go with the sodium bromine and just resign myself to the fact that I will have a high chlorine demand until the bromine is consumed by sunlight and chlorine. Monocloramine is nasty stuff in my opinion but it does work. I am less enthused about the linear quat algaecide. Your pool will look like a bubble bath for a while and it will be very irritating to the eyes.
I would definitely look into the product for biofilms but I would not get my hopes up. It seems that biofilm eradication has become the NEW phosphate remover to the pool/spa industry since the price of lanthanum salts has gone way up. Everything from enzymes to sphagnum moss (really? REALLY?!?) to sodium metasilicate/sodium carbonate/potash alum are being used in these new miracle products

[PoolDoc]

The OP -- smullins34 -- is running at least 2 threads on this topic, one here and one at TFP.I'm going to ask him to pick one or the other. But I'm closing this thread till he does.

She thought it was ridiculous that I didn't want her to waste our time, so I have enthusiastically supported her right to use another forum.

BUT . . . it's a good topic, and I'd like to use Waterbear's and my posts as the basis for a sticky on this later on. So, I've cleaned up some of the OT stuff (no blame -- I do it too!)

If you have any experience on this issue, please share!