CuLator Metal Removal

[chem geek]

[EDIT] NOTE: I received some info from the President and CEO of CuLator and am currently reviewing it so I will update this thread later. Some of the information in my posts may be inaccurate so I will let you know once this is sorted out. [END-EDIT]

Copper is usually better at killing algae than bacteria. Silver is usually better for fecal bacteria, though depends on the strain. Kill times are shown in this post. The kill times for copper and silver are substantially slower than that for chlorine against most bacteria.

Note that in this link very high chlorine levels are not needed if instead lower chlorine levels are consistently maintained. Shock chlorination in their example would be 200 ppm.

Basically the iron bacteria are no different than any other in terms of how they behave with chlorine and free-floating (planktonic) bacteria will not grow under normal chlorinated conditions since they are killed easily and quickly. Just like other bacteria, if they are not killed first and instead allowed to form biofilms, then that requires superchlorination or other techniques to remove the biofilm.

As for organic matter, high chlorine levels should not cause them to stain. High chlorine levels cause metal to stain primarily due to the higher pH if you SLAM with a hypochlorite source of chlorine. The metal itself (such as ferrous iron) is oxidized rather quickly by chlorine so it is incorrect to say that shocking with chlorine oxidizes the metal. What is more likely is that it oxidizes any metal sequestrant and that would then release the metal that used to be sequestered so it could then stain.

According to this MSDS, Bio-Dex Protect-All Supreme is rather acidic (pH < 2) and is a bio-degradable surfactant. It is not a metal sequestrant and instead is used to remove or prevent calcium buildup and organic stains. They note that "The initial dose of the product may reduce chlorine levels." which implies that it reacts with chlorine. It is their Aquadex 50 Stain Off product that Bio-Dex recommends for removing metal stains and this product and this MSDS indicates that it has TrisodiumHydroxyethylethylenediaminetriacetate as its primary ingredient so that would be a non-phosphate based metal sequestrant. Perhaps they referred you to the wrong product. HOWEVER, that ingredient is nothing more than the salt form of EDTA and we already know that this is not as strong a metal sequestrant as HEDP and furthermore that it breaks down more quickly from chlorine.

 

[doubleOkevin]

Excellent link. What sucks about this particular situation is that raising the chlorine will make the stains return. That's why I'm hoping the copper treatment will actually help. Unfortunately the link doesn't touch on the use of copper to kill iron bacteria. I do recall the Periodic Products agent saying that they have had success with it though.

 

[doubleOkevin]

They never actually said that the protect all supreme was a sequestrant. I just assumed. However, they did say it works to prevent metal staining, which is all I care about. The bottle does say it controls iron and rust so maybe it works differently than a sequestrant. I have no idea. I'm just speculating at this point. They never mentioned the Aquadex, but I suppose it's possible they were mistaken. Also, Im curious. If it removes calcium, which is a metal, why wouldn't it have the same effect on other metals?

 

[chem geek]

[EDIT] NOTE: I received some info from the President and CEO of CuLator and am currently reviewing it so I will update this thread later. Some of the information in my posts may be inaccurate so I will let you know once this is sorted out. [END-EDIT]

Because there are many different ways of preventing calcium scaling that have nothing to do with sequestering it as a metal. The scale growth can be inhibited by interfering with crystal growth formation. Existing scale can be removed through lower pH and creating conditions that accelerate dissolving (what surfactants can do). The surfactants and lower pH can also help to remove other metal staining, but they won't sequester the metal so the staining can come back when the pH rises again.

You can certainly try the product and let us know if it works, but it sounded like you wanted to get out of having to continually add product to prevent metal staining.

 

[Patrick_B]

Yes, I'm interested in hearing how this works out as well.

 

[chem geek]

As we noted earlier in this thread, water wells can have iron bacteria. While many municipal water districts use water sources from reservoirs, lakes and streams, Pensecola where doubleOkevin is from does have their municipal water come from wells as described in this link.

Treatment options for wells with iron bacteria are described in this book. Copper is mentioned as sometimes being used and another source sent to me from the President/CEO of CuLator showed it being used at 3 ppm, but that's very high and could cause copper staining unless the pH were kept quite low.

This paper (which unfortunately one must pay for) describes how iron bacteria ARE killed if the chlorine level is maintained. They tried 0.1, 0.2, 0.4, and 0.6 mg/L of chlorine and all prevented such growth through when they stopped the treatment the 0.1 had the bacteria come back after some days indicating that they were not completely killed. Remember that 0.1 is roughly and FC/CYA ratio of 10% so a SLAM level of chlorine should readily kill off the bacteria completely IF they weren't in biofilms or their thicker filamentous form. The paper indicates that in this form it takes 25 mg/L of chlorine to get rid of the bacteria.

As noted in this paper, Mycobacterium are fairly resistant to chlorine where M. fortuitum has a CT value of around 45 for a 1-log reduction and a CT of around 15 for a 0.3-log reduction (i.e. killing half). This means that for a 15 minute generation time (doubling of population) that 1 mg/L of chlorine would be needed to just barely prevent uncontrolled bacterial growth. This is over 10 times higher than the active chlorine level in TFP pools that is in the 0.05 to 0.1 range. It's somewhat less than double regular SLAM levels and is less than yellow/mustard SLAM level. On the other hand, I have not yet found any evidence that iron bacteria are as resistant to chlorine as Mycobacterium.

 

[doubleOkevin]

Just an update to the situation. I added copper to the pool along with protect all supreme and CuLator pack in the pump basket. Also put 2.5 gallons of sodium hypochlorite (liquid chlorine) in the water after adding all the other chemicals. It is roughly a 20,000 gallon pool. Usually adding this much chlorine would cause the stains to reappear in a couple days. Well I did all that 3 days ago and just went by to check on it and the liner looked better than I've ever seen it. This is very encouraging, but I'd like to see what happens when the protect all wears off over the next couple weeks.

 

[chem geek]

Shouldn't you notice some discoloration of the CuLator packs if they are taking out a lot of metals? Since you added copper, I figure they would take that out at some point. If the iron is still not taken out, then the Protect All Supreme would just be another product you'd need to add to prevent metal staining so hopefully their procedure is actually killing off the iron bacteria and making the CuLator then remove the iron physically from the pool. Let us know how it goes after the Protect All Supreme wears off.

 

[doubleOkevin]

It's been a month since I last posted on this thread. I went by the pool again today and the stains are not coming back. It's been more than enough time for the Protect All to wear off, so my conclusion is the CuLator guys were right! I'm extremely pleased with this outcome. You have no idea how much of a headache this "iron bacteria" has been. To summarize what I did, I removed the stains with Citrus Treat (ascorbic acid). Then I added Protect All, CuLator Power Pak 4.0, full bottle of Swimtrine Plus copper algaecide, and 2.5 gallons of sodium hypochlorite all at once. The agent recommended using a non chelated copper (copper sulfate) over the Swimtrine plus since it was what was mentioned in the literature, so the next day I went back and added 1 lb of copper sulfate (Root Kill). For the next month and longer I have been keeping the chlorine at 5ppm and above with a 50 cya reading. Got there today and the pool looks great.

Also, no signs of copper staining either. The CuLator Power Pak turned pretty blue and every time I backwashed, the water was milky blue. Probably not too much copper left in the pool and if there is, it's not staining.

 

[chem geek]

Thanks for reporting back. So what I would say about CuLator is that if it doesn't appear to be working for whatever reason, call the company and have them help. That may significantly improve the mixed results we've had reported from using this product. It may just be more complicated in quite a few pools and need more than just putting it into the skimmer and hoping it works.

It's also good that there's pretty positive feedback of metal removal from the CuLator pak turning color as well. Of course, you added copper to the pool with the copper algaecide so I'd expect the CuLator to remove that, at least, but the point is that after removal of that copper the stains do not appear to be coming back.

 

[TreeFiter]

Was your pool filled from a private well? Iron bacteria are almost unheard of in municipal water supplies.

I just had a very similar conversation with the people at CuLator today, and they were saying that apparently Iron Bacteria isn't exactly unheard of in municipal water supplies. They have been working with various members of the water treatment industry regarding this same issue. In water treatment, they have had success with using a copper algaecide and chlorination to kill off the iron bacteria.

I have to say, the people at CuLator have been extremely helpful. They will bend over backwards to help you solve your metals problems. I'll admit that I'm still struggling with one of the pools I have used it in, but there are others that it has worked very well in. What I have taken away from my experience with this product is that it is NOT a simple, any idiot can do it, kind of fix. It requires a fair amount of understanding of the chemistry involved, and then there are the difficult situations like with Iron Bacteria. You can't simply drop it in your pool and expect your problems to disappear. That being said, I do believe it works.

 

[rcy]

I might have been one of the first to (unscientifically) test a CULator back in 2011. I've been getting metal staining the past couple of years (copper) and I long ago removed the mineral cartridge in my DuoClear so it can only be coming from my pool heater. This year has been especially bad (the pool heater is now in it's ninth season, and I have a salt pool...level about 4000ppm salt so maybe it's time for new heater, or a low salt system??)

Anyway, aside from all that, I threw a CULator in about a week ago and just cut it open. The powder in there is pure white when new (the pool store actually cut one open for me). Based on the colour of the powder now (a greenish/blueish colour - I hope it shows on your computer screen), I'd say that it's removing copper from my water. Copper was .4ppm when I tested it before the CULator. Haven't had it tested since the CULator, but I think the picture is compelling. I had this same result last year (or was it the year before..lol??) where the powder changed colour.

I did notice they recommend leaving the pouch in for 30 days now. Originally, it called for two days, if I recall correctly.