Bio-film - Par Pool & Spa has one of the best handles on how to recognizing & treating this problem; it is the root cause of White Water Mold & Pink Slime and other problems.  If you haven't dealt with it yet, you will. Read about Bio-films here.

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Question:
I found your company by searching for a solution for "Pink" algae (pink slime) and white water mold. I know I had both.

I physically removed all signs of the pink slime, and have been shocking my pool excessively for the past couple of weeks. I am now putting two pounds of Calcium Hypo chloride in my pool every night to try to keep the free chlorine level up. I know that this is the wrong type of shock to use with a salt water pool, but the local pool store owner recommended it to raise my calcium hardness.

My problem is the chlorine disappears during the day. Last week after Super Shocking the pool (by recommendation of a pool service man), The free chlorine went from 50 ppm to less than 0.5 ppm in one day. We used 17 pounds of Sodium Dichlor shock.  I believe that I have a biofilm in the underground plumbing causing the high chlorine demand.

My pool is 13,500 gallons. One piece fiberglass construction. Cartridge filter (Unicel 175, new this season). Hayward Goldline Aqua Logic controller with a T-15 salt cell. The entire system is on it's 4th season. The salt cell controller indicates that it is using just over 6 amps when on. The pump/filter is set to run 16 hours a day, with the chlorinator set at 50% (8 hours). According to a service technician from Goldline, my cell is producing chlorine as long as there is more than 4 amps drawn when running.

My questions to you are:

Is the [AquaFinesse] Pool Puck compatible with a salt water pool?

Do you think, based on what I have said, that the Pool Puck will help eliminate my chlorine demand?

Will high Cyanuric Acid levels affect the Pool Puck? My CYA is between 200 and 300 ppm from the excessive dichlor shock.

Sorry for the long explanation, but I want to include all information so you could give me an educated answer.

Thank you for taking the time to read and answer this.
Barry Sherman

Response:
Hi Barry,

Shawn & Steven from AquaFinesse forwarded me your question & I would like to help you as best as possible. You do have several things going on & I'll give you basic answers but would prefer if you could call me so that I can answer them with some depth plus do a few follow-up questions for clarification.

1. Yes, pink slime & WWM do grow & fester even in salt chlorine treated pools. I am assuming that you have had the pool for a while but the AquaRite & salt system is a relatively new addition to the pool.

2. The PS & WWM, we have found, are both "off-shoots" from the bio-film. It is very likely that the infestation begun a while ago. Possibly last year. By the way, where do you live? & Tell me more about the pool.

3. You can have severe chlorine demand issues with a salt system. Your situation is "made worse" with the addition of the dichlor. There's nothing wrong with the cal hypo, especially if your Cal. Hardness is low. Unfortunately, the more dichlor that is added the higher you will drive cyanuric acid. Over 100 ppm, it should be diluted by adding fresh water. In your case you may have to drain & refill about 1/2 of the pool. This deserves a longer/better explanation.

4. We have experienced great success with our customers around the country in using AquaFinesse Pool Pucks and treating chlorine demand. One customer who is a NASA engineer living in MD had a fairly severe chlorine demand back in June. We got the demand under control & he is using Pool Pucks to control the bio-film. Just received a note from John on 08/07/09 with an update: he's still in very good shape.

Please call me & let's talk more about HOW to get your pool under control. 203-377-0100. Looking forward to the call.