Successful treatment of "pink algae"

Hi all,

I live in the Northeast where I’ve used my in ground pool from June to late September. Last year I started using a solar cover and I got a “pink algae” infestation. This was my third year of having my pool.
I did some homework and I found three suggested treatments:

A regular chlorine shock won’t cure Pink Algae. (It’s not an algae, it’s a bacteria!)
Pink Treat is sodium bromide and the active agent is the hypochloric acid which is formed when you shock the pool after adding Pink Treat. Pink Treat may do the job, however, once you use it your pool is converted from a chlorine pool to a bromine pool. Your chlorine consumption will always be higher.

There’s a ProTeam product which is VERY expensive.

I checked out Yellow Out http://yellowout.com/index.html by Coral Seas and called them up. They promised me that it would help. It did. Here’s the cleanup procedure:



1. Do you have “Pink Algae”?

If it’s pink, if it’s on the pool surfaces and crevices and if you can brush it off, then it is!
I’ve found that the term “pink slime” used for the Pink Algae is misleading.

2. Preparation

Do not skip this part!
Raise the water level by 2 – 3 inches.
Raise the water pH to 8 – 8.4.
Throw into the pool whatever had been in contact with the water (floats, brushes, noodles, goggles, vacuum hose, etc.)
If you hadn’t back-washed your filter recently – do it now.
Make sure you have enough chlorine for three super shocks. (I used 50% more than my regular dose of two packs for a 20,000 gal pool).
Stock up on a heavy dose of water clarifier. I used both a regular soluble clarifier and BioGuard’s “Sparkle Up” additive to my DE filter (see below).

3. Yellow Out application.

Stop the main pump operation.
Have in one hand a container with “Yellow Out” (YO) and in the other hand an equal amount of your chlorine shock compound. I used altogether three lbs of each and used three doses of 1 lb at a time.

Spread the YO near areas of infection and immediately an equal amount of chlorine at the same location. Let them mix in the water. Spread one can of 1 lb at a time. The trick is to spread a small amount of YO followed by an equal small amount of chlorine.
When you are done spreading all the ingredients, if you have a solar cover, spread it over the pool as you normally do.

DO NOT OPERATE THE MAIN PUMP FOR 8 HOURS.

4. Post-YO application Circulating

Reel up the solar cover and rinse both sides as you reel with a water hose.
If you can see the pink algae on the walls brush it off.
Keep on brushing later as the water clarity improves.
Start operating the pump. If your bottom drain operates and if you can regulate it, circulate through it only.
If not, use the vacuum line immersed at the pool’s deep end for pump intake.
REMOVE ALL CLOCK STOPPERS FROM PUMP’S CLOCK.
You’ll be circulating continuously for about 48 hours.

5. Second Shock

Shock 12 hours after the first treatment.

6. Third Shock

Shock again 12 hours after previous shock.

7. Reinstating water chemistry

pH should go back to 7.4. If it doesn’t ask the pros what to use for your pool. Fred from Coral Seas says not to worry about it – it’ll go down by itself. If the water is not clear (my water clarity was very low after the YO application) use a good amount of clarifier. If the pressure in your filter goes up by 5, back-wash it. I backed-washed mine twice and used BioGuard’s Sparkle Up added to the DE to aid filtration after the second back wash. Read label instructions how to apply the DE-Sparkle Up mixture. It’s easy.
Most likely a third back-wash wouldn’t be necessary.

8. Resume normal pump duty cycle (12 hour cycle) after water clarity has returned to normal. You should vacuum the bottom and walls and use robotic cleaners if you have one after the third shock. Pool should be clear after 48 hours of non stop circulation and vacuuming.

9. Sanitize all bathing suits that had been used in the pool by soaking them in a washing machine detergent. Use bleach if not prohibited by washing instructions on bathing suit label. I used Lysol too.

10. Double your normal stabilized chlorine dose. I am using 4 tablets now instead of 2.
Chlorine level is now 4-5. Keep it this way for a couple of weeks and then resume normal level.

11. Keep Shocking every week.

12. If you have any questions call Fred at Coral Seas. He’s an experienced pro.
Leslie can give you the basics but Fred is the lead man.
The 800 number is available on the package label and in the website.

Actually, both the inorganic ammonia products (such as yellow out) and the sodium bromide products work in the same way. They convert the chlorine in the pool to either monochloramine or hypobromous acid (bromine sanitizer), depending on whether you use the former or the latter, and in doing so take the CYA out of the equation. This is equivalent to having a MUCH higher ACTIVE FC level than you have. They are useful if your CYA is high (which is usually when pink algae starts) You CAN kill pink algae with plain chloirne but it takes VERY HIGH levels, higher than even mustard algae.

BOTH inorganic ammonia and sodium bromide product create a hugh chlorine demand after their use to destoy the sodium bromide or monocloramine that is formed so in this repect they can both be a cure worst than the disease. The only difference that the inorganic ammonia proucts have is that monochoramine does offer a bit of protection against UV light so the monochloramine might allow the chlorine to stay in the pool (but it will be in the form of CC).

I noticed that you are using trichlor. I am betting that your CYA levels are high. That is the reason you got pink algae in the first place. If you maintain your water chemistry properly, including CYA levels, then pink algae is not a problem in chlorine pools. IF you post a full set of test results I bet we would find them interesting.

I hadn't gotten the pink algae during the two previous seasons, until I started using the solar cover on the third. The previous owner of the property had also used trichlor with no problem. Is it possible that the solar cover was the culprit?

Quote:

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Originally Posted by waterbear

Actually, both the inorganic ammonia products (such as yellow out) and the sodium bromide products work in the same way. They convert the chlorine in the pool to either monochloramine or hypobromous acid (bromine sanitizer), depending on whether you use the former or the latter, and in doing so take the CYA out of the equation. This is equivalent to having a MUCH higher ACTIVE FC level than you have. They are useful if your CYA is high (which is usually when pink algae starts) You CAN kill pink algae with plain chloirne but it takes VERY HIGH levels, higher than even mustard algae.

BOTH inorganic ammonia and sodium bromide product create a hugh chlorine demand after their use to destoy the sodium bromide or monocloramine that is formed so in this repect they can both be a cure worst than the disease. The only difference that the inorganic ammonia proucts have is that monochoramine does offer a bit of protection against UV light so the monochloramine might allow the chlorine to stay in the pool (but it will be in the form of CC).

I noticed that you are using trichlor. I am betting that your CYA levels are high. That is the reason you got pink algae in the first place. If you maintain your water chemistry properly, including CYA levels, then pink algae is not a problem in chlorine pools. IF you post a full set of test results I bet we would find them interesting.

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When the proper amounts of hypochlorous acid and the inorganic amonia (Yellow Out) react in the proper moderately high pH one atom of chlorine is transfered from the former to the latter and the monochloramine is formed. If this species is more effective in oxidizing organics than HOCl this is fine, however, where's the higher chlorine intake? You simply made your available chlorine more "potent" because the NH2Cl is more active than the HOCl.
Maybe what you mean is that further superchlorination will transform the residual monochloramine to di and tri chloramines, and these, in turn, have to be broken down by further superchlorination as well. But this should be a one time process. However, since the monochloramine does the job on the organics, there's no need to continue and chlorinate it because the end product,once the chlorine atom of the monochloramine did its job, is harmless. Did I miss something? If you have links to the underlying chemistry please post.

It is NOT more effecient at oxidizing organics. Monochloramine is a less potent oxidixer than hypochlorous acid. What happens is twofold. First and formost, monchloramine is a nitrogen containing compound and as such is a primary food for algae and many bacteria. It is actaully consumed as such and the "attached" chlorine kills the algae or bacteria from within. The second thing that happens is that the ammonia competes with the cyanuric acid in the water for the chorine and in this way 'deactivates' some of the CYA temporarily so the chlorine becomes more 'active' or effective at killing the algae or bacteria. This is also why sodium bromide becomes very effective since it essentially take the CYA out of the loop, so to speak since the chlorinated isocyanurates, which are the primary form of chlorine in a pool with high cyanuric acid levels readily oxidize the bromide ions to hypobromous acid which is much more potent than the clorinated isocyanurates.
These types of products are much more effective when the cyanuric acid levels in the pool are high and not as effective when they are in more normal ranges. Also, these types of bacterial growth do not occur in chlorine pools when the cyanuric acid levels are normal since more of the chlorine exists in the form of hypochlorous acid and not as chlorinated isocyanurates. Remember that monochloramine IS a chloramine and is not considered to be a desirable form of chlorine in the pool and is, in fact, one of the combined chlorinamines that we test for and eliminate by shocking the pool. Why? Because they are NOT as effective sanitizers or oxidizers as hypochlorous acid BUT when there is a high level of cyanuric acid in the water there is a very low level of hypochlorous acid. Most of the chlorine is in the form of chlorinated isocyanurates unless additional hypochlorous acid well over what is normally needed is introduced to move the equalibrium point of the reaction. (In other words, if your CYA is high you need to run MUCH higher FC levels and shock to much higher levels to have the same activity that you would have with CYA in the 30-50 ppm range and FC in the 3-5 ppm range.

As to why this occured in the third year of using trichlor the reason is simple and had NOTHING to do with your solar cover. Using stabilized chlorine causes the CYA to rise over time and the pool becomes overstabilized. I am interested at what your CYA level actually is. Would you post a full set of test results? Also, what kind of filter do you have. I believe in another thread you said a DE filter but is it a 'bump' flter or a backwashing filter? Remember that it got higher as each year passed and that third year is when it reached 'critical mass' and you developed the pink slime. This is a very common symptom of overstabilizd pools, btw.

As far as a more in depth discussion of the chemistry involved, the place to have that would be in the 'china shop' section of the forum since it really is beyond the scope of what the forum Administrator (Pooldoc) wants discussed in the general areas of the forum. You might want to review some of the info in the forum (and possibly some of the info over at Troublefreepool.com) about the chlorine/cya relationship and it's effects on pool chemistry. A good place to start is Pooldoc's sticky on his 'best guess chart' on chlorine levels for different levels of CYA that was posted by Watermom, one of the mods here.
http://www.poolforum.com/pf2/showthread.php?t=365

You can also search here or at Troublefreepool for posts by chemgeek. He has posted quite a bit of the theorectical chemistry on the chlorine/cya relationship.

Thank you, Evan, for this detailed post. I’ve never seen anything more comprehensive on this topic before. The only thing that you missed are chemical equilibrium and kinetics constants of the reactions involved (just kidding…)

I inherited this pool from the previous owner of this property, which I bought three years ago.
BTW, I chose Water_man as my user name for a reason. I spend a LOT of time in the pool, to a degree that I’ve told my friends that I didn’t buy a house with a pool – I bought a pool with a house…

The pool is 28 years old, and to the best of my knowledge it has never had pink algae, although I’ve been using it in the last three seasons more than the previous owner has ever done for 25 years....
Since the pool is in New England, it’s open during early June through September.

I opened the pool on this Friday. Here are the numbers of the water analysis, done by the store’s colorimeter:

FC 0.22
TC 0.56
pH 7.9
CH 171
TA 101
CYA 56
Cu 0.22
Fe 0.38

You may be right about the CYA level and the possible ineffectiveness of my previous superchlorinations. I used to shock with 2 bags of calcium hypo, yielding 10 ppm FC, while "The Table"
shows that 20 ppm is the desired level.

My DE filter is a backwash type filter (Anthony Apollo VA 38 – 38 SF area) and I BW it frequently as needed (either when the pressure rises by 8 , or at least once a season.)

My pool opened as a swamp. Here’s why:
We had a lot of rain this winter and although I drained my pool upon winterizing about two feet, it got refilled during winter and the winter cover (mesh type) touched the water. I didn’t anticipate the unavoidable results of the combination of leaves and tree debris on top and the contact with my pool water, although the winterizing algaecide should have done its job. Next closing I’ll be smarter – I’ll have the submersed pumps in the pool ready in place, and one I notice the cover submerged I’ll pump out.

As to the green pool: I already shocked with bleach to a 20 ppm level and now the filter is working its a** off to clear the water. The green is gone. All I have is brown precipitate of dead algae, and bluish looking water with high turbidity. But I’ve done my reading here and elsewhere and I’m not panicky. I wonder if any “filtering aids” should help.

Last but not the least. I’d like to show my appreciation to the owner of the site and to make a donation.
Is this is commonly practiced and accepted, or, should it be better to subscribe to the sister site?
Regards,
Mike

Quote:

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Originally Posted by Water_man

Thank you, Evan, for this detailed post. I’ve never seen anything more comprehensive on this topic before. The only thing that you missed are chemical equilibrium and kinetics constants of the reactions involved (just kidding…)

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I save that kind of stuff for the 'china shop' section of the fourm:D

One other thing you can try is a "skimmer sock" It goes in the skimmer and collects the very fine particles. You can find them on the internet, or at some pool stores. You can also cut a pair of pantyhose and tie it off and put it over the skimmer basket. As for donating to this site - you used to be able to, but I don't think you can anymore. There is an owner of the site, but he has been missing from here for a while. The good moderators have kept up the site using all of their knowledge to help:) We all appreciate them so much:) Just keep posting and the good people here will help you with any question you have. Welcome to the forum.

Quote:

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Originally Posted by mbar

One other thing you can try is a "skimmer sock" It goes in the skimmer and collects the very fine particles. You can find them on the internet, or at some pool stores. You can also cut a pair of pantyhose and tie it off and put it over the skimmer basket. As for donating to this site - you used to be able to, but I don't think you can anymore. There is an owner of the site, but he has been missing from here for a while. The good moderators have kept up the site using all of their knowledge to help:) We all appreciate them so much:) Just keep posting and the good people here will help you with any question you have. Welcome to the forum.

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Skimmer sock : another great idea I learned about in this forum.
My previous dying pump almost choked on it, but my new pump is unaffetcted. I'm amazed by the amount of fine particles it blocks. Cleaning it every few days by a garden hose is easy and it's worth the smal effort.

Will it hurt to close the pool for the season if you haven't fully rid of the "pink" bacterium? I'm trying to shock the crap out of the pool after scrubbing and vacuuming it down, what else can I add to help kill this stuff? I was hoping to close in 3 days?????? Help?

If you don't kill all of the "pink" bacterium, it'll still be waiting for you when you reopen in the spring, and likely make your water worse as well because any chlorine you put in to winterize will just be used up fighting the pink stuff. Can you please post a set of current numbers taken with a drop-based kit, so maybe we can help you get it accomplished quicker?

Jante