Possible Algae In Copper Ionized Inground Pool

[Kschisano]

Hi,

I have an 18x36 inground pool that uses a copper ionization system. I have been noticing green on the sides of my pools and will rush it away only for it to come back the next day. Is there something I should be putting in the pool to prevent this? Is there a problem with our ionization system? I would really appreciate any help on this topic and the maintenance of a copper ionized pool in general - we just moved into our house and are very unfamiliar with this type of pool. TIA

[Michael Assad]

Which ionization system are you using?

I have you tried AquaFinesse? It breaks down the biofilm on the walls so that the ionizer can get at the algae.

[chem geek]

We'll let Michael take care of you since you could easily manage your pool without the ionization system by properly maintaining a Free Chlorine (FC) level that was at least 7.5% of the Cyanuric Acid (CYA) level. This is equivalent to less than 0.1 ppm FC with no CYA and is what tens of thousands of pool owners who are members of various forums including The PoolForum and Trouble Free Pool are doing and where there are over half a million visitors per month to these sites. These pool owners use chlorinating liquid or bleach plus a small amount of acid and use NO clarifiers, flocculants, enzymes, algaecides, phosphate removers, "shock" products or anything else.

Good luck with your ionizer system.

[waterbear]

Bottom line is this. Copper has kill times that are too slow to maintain sanitized water under real life conditions. It is NOT an EPA approved primary sanitizer. Period! It is really just an algaecide. If you have algae in a pool with copper then you probably don't have a working ionizer and do not have sanitized water.What is your copper level and are you running any chlorine residual (which is required, btw, to kill viruses and other pathogens that copper can't.)

[Michael Assad]

 

Bottom line is this. Copper has kill times that are too slow to maintain sanitized water under real life conditions. It is NOT an EPA approved primary sanitizer. Period! It is really just an algaecide. If you have algae in a pool with copper then you probably don't have a working ionizer and do not have sanitized water.What is your copper level and are you running any chlorine residual (which is required, btw, to kill viruses and other pathogens that copper can't.)

 

I agree. You still need chlorine in the pool, but not as much. You also don't spend as much time balancing chemicals.

EPA and Health Canada have approved "copper ion releasing devices" for 0.5 to 0.6 ppm chlorine vs. 3 to 5 ppm recommended without it. So they agree that they work, but are not stand-alone systems.

I'm not sure how the 3-5ppm Cl converts to FAC though...

Ionizers are very effective at killing algae. This allows the chlorine in the water to work more effectively so you can safety reduce the concentration.

Some people like the idea of not having as much chlorine in the water, and want a pool that is easier to maintain. Thus, the ionizer. Problem is there are many crappy models on the market that cause staining and so they have gotten a bad name in some circles (like this one )

[chem geek]

Copper is an effective algaecide, but the point you are missing is that chlorine alone is also an effective algaecide if the FC is maintained at 7.5% of the CYA level and you miss the fact that the active chlorine level is VERY low when CYA is present. The detailed chemistry may be seen by reading the "Chlorine/CYA Relationship" section in the first post in the thread Certified Pool Operator (CPO) training -- What is not taught. In a swimming pool with the FC at 7.5% of the CYA level which is enough to prevent green and black algae growth regardless of algae nutrient (phosphate, nitrate) level, the active chlorine (hypochlorous acid) level is roughly the same as a pool with less than 0.1 ppm FC with no CYA. Most of the chlorine is bound to CYA and essentially inactive (less than 1/150th as reactive as hypochlorous acid).

We deal primarily with factual truthful information in peer-reviewed papers in respected scientific journals and then match such information to the experiences of tens of thousands of swimming pool (and spa) owners. I don't work in the pool or spa industry and am not selling nor pushing any particular product. I am not paid for anything I write. Nevertheless, anyone can write anything in these posts which is why I refer to the true science so that anyone can verify what is factual and true.

[Michael Assad]

So why does the EPA and Health Canada say I need 3 - 5 ppm of chlorine?

Isn't CYA also toxic?

[chem geek]

Neither the EPA nor Health Canada understand the chlorine/CYA relationship. The swimming pool industry has done an excellent job for 40 years obscuring that relationship claiming that "CYA doesn't matter, only FC matters" when that is simply not the case. So later on this shifted to "CYA reducing chlorine's effectiveness" but not saying by how much nor the fact that the opposite is true -- that using chlorine at recommended FC levels with no CYA is OVER-CHLORINATING because the active chlorine level is too high.

The EPA limits chlorine to 4 ppm, but some states (see this post) allow up to 10 ppm, but that's because CYA is used though the codes don't explicitly tie the two together as they should.

CYA is not toxic. It's less toxic (LC50 > 5000 mg/kg) in concentrated form than table salt (LC50 = 3000 mg/kg) and aquatic toxicity is also very low (lowest is Rainbow Trout at 1080 ppm for 96 hours).

[Michael Assad]

 

Neither the EPA nor Health Canada understand the chlorine/CYA relationship. The swimming pool industry has done an excellent job for 40 years obscuring that relationship claiming that "CYA doesn't matter, only FC matters" when that is simply not the case. So later on this shifted to "CYA reducing chlorine's effectiveness" but not saying by how much nor the fact that the opposite is true -- that using chlorine at recommended FC levels with no CYA is OVER-CHLORINATING because the active chlorine level is too high.

The EPA limits chlorine to 4 ppm, but some states (see this post) allow up to 10 ppm, but that's because CYA is used though the codes don't explicitly tie the two together as they should.

CYA is not toxic. It's less toxic (LC50 > 5000 mg/kg) in concentrated form than table salt (LC50 = 3000 mg/kg) and aquatic toxicity is also very low (lowest is Rainbow Trout at 1080 ppm for 96 hours).

 

Sounds complicated. We have an ionizer at the cottage and we put 1/2 a chlorine tablet in the floater once every 1-2 weeks and that's it. We have renters coming and going, kids, big families, etc. and the water is always crystal clear. There is virtually no chemical balancing or maintenance required.

I don't understand why there is so much hate for ionizers when they are a great solution for many cases.

[chem geek]

It's not complicated -- it's just facts that dispute what you were claiming (CYA being toxic, for example).

The reason to avoid copper is that when things go wrong with metal staining, it's VERY expensive or difficult to deal with. If you look at the many posts on more frequented pool forums you will find that there are quite a few incidents where people get copper staining in their pools. The copper test kits are not that great and you also have to maintain pH. In some pools the pH tends to rise over time. In your situation using Trichlor tabs, the pH won't rise so much and may drop without pH Up addition because Trichlor is so acidic, but for every 10 ppm Free Chlorine (FC) added by Trichlor it also increases Cyanuric Acid (CYA) by 6 ppm. This makes the chlorine less effective over time and is why algae can grow faster than chlorine can kill it.

If you keep using Trichlor tabs and do not change or refresh the water, then the CYA level will build up and up. Eventually that will slow down oxidation of bather waste and reduce pathogen kill times to unacceptable levels. This is why chlorinating liquid or bleach is recommended as the primary source of chlorine. Trichlor tabs are fine for vacations, but the CYA buildup can be a problem.

If you really want to go down the route of using Trichlor tabs and not worry about algae growth, then instead of using copper ions that can stain and turn blond hair greenish, you can instead use a phosphate remover or use Polyquat 60 weekly neither of which will have these side effects.

[waterbear]

 

 

Neither the EPA nor Health Canada understand the chlorine/CYA relationship. The swimming pool industry has done an excellent job for 40 years obscuring that relationship claiming that "CYA doesn't matter, only FC matters" when that is simply not the case. So later on this shifted to "CYA reducing chlorine's effectiveness" but not saying by how much nor the fact that the opposite is true -- that using chlorine at recommended FC levels with no CYA is OVER-CHLORINATING because the active chlorine level is too high.

The EPA limits chlorine to 4 ppm, but some states (see this post) allow up to 10 ppm, but that's because CYA is used though the codes don't explicitly tie the two together as they should.

CYA is not toxic. It's less toxic (LC50 > 5000 mg/kg) in concentrated form than table salt (LC50 = 3000 mg/kg) and aquatic toxicity is also very low (lowest is Rainbow Trout at 1080 ppm for 96 hours).

 

Sounds complicated. We have an ionizer at the cottage and we put 1/2 a chlorine tablet in the floater once every 1-2 weeks and that's it. We have renters coming and going, kids, big families, etc. and the water is always crystal clear. There is virtually no chemical balancing or maintenance required.

I don't understand why there is so much hate for ionizers when they are a great solution for many cases.

 

And in this thread

http://www.poolspaforum.com/forum/index.php?showtopic=23624#entry178880

you posted this so you are certainly NOT unbiased and not necessarily presenting the facts from a neutral standpoint as chem geek (and my self since I no longer actively work in the industry and represent NO industry interests)  

[DISCLAIMER: I represent an ionizer manufacturer

 

[chem geek]

It's even more than that as the LinkedIn profile shows Michael being VP of Sales & Marketing at Argenia Systems Inc. which has railway safety technologies as well as the ClearBlue copper ionization system. Based on this post it sounds like it was Michael's wife who worked at Argenia and then Michael went over there to work in January.

On the plus side, unlike some ionizers ClearBlue as described in this link and this link uses copper, silver, and zinc in an 8:1:1 ratio so at least with the silver and copper there is additional control of bacterial growth including fecal bacteria (unlike copper alone which is mostly algae prevention). The zinc is there for the silver and zinc combination to allow for a lower copper concentration that still inhibits algae growth and therefore reduces the risk of staining. However, without feedback controls that know the degree of water dilution and metal adsorption/removal in the pool, there is still the risk of under or over shooting the metal ion concentrations to either no longer prevent algae or to have metal staining especially on plaster surfaces. This is what we most commonly see get reported when things go wrong -- either these systems aren't working and get algae anyway or they stain plaster or turn blond hair greenish. If one were to accurately test the metal ion levels (especially for copper) AND one were to make sure the pH didn't get too high then one has a better chance of making such systems work more reliably.

Of course, proper maintenance of the FC/CYA ratio will also prevent algae growth by itself, but if one wants a lower ratio then use of weekly Polyquat 60 or a mostly one-time use of a phosphate remover (with occasional maintenance doses as needed) would accomplish the same goals without the risk of side effects.

[Michael Assad]

I have nothing to hide That's why I use my real name and the same profile pic for LinkedIn, Twitter, etc.

The first thing I ever posted in this forum was the disclaimer that I represent an ionizer manufacturer.

The fact remains that I believe in ionizers, as I see them selling and I hear the praise from customers[/url].

Everything I've said and will say is unbiased and factual, as per the terms of the forum (and because I'm a decent human being )

[chem geek]

Not saying you were anything but up-front, but your sample size for your product is too small and narrow. If someone set your unit up too high to add too many metal ions and they let their pH get high, they could most certainly get staining. If you used your system right away in a freshly plastered pool, then that would also be a problem given the very high pH of such new plaster. It's not that one can't make the system work, but rather that there are risks if it doesn't. Whereas the risks of using chlorine tend to be not using enough so one gets algae, that is easy to treat with more chlorine whereas copper stains can be very difficult to remove (unlike iron stains that are far easier; silver stains are even worse).

Also, there are ways of accomplishing the same thing you are doing with no metal staining nor blond hair greenish risks AT ALL. Namely, one can use Polyquat 60 weekly or one can use a phosphate remover either of which prevent algae from growing as quickly so let one use a lower active chlorine level if that is what they want to do. There's one forum user on another forum who wants a lower active chlorine level and was thinking that his ozonator was the reason for his success but he just completed experiments proving that the ozonator wasn't the reason and that low phosphate levels were why his pool didn't get algae so now he's going to use a phosphate remover. The ozonator was useful for keeping CC's low since he kept the pool covered a lot of the time and had the active chlorine level low. For those with a recommended active chlorine level and some exposure of the pool to sunlight, there are no CC issues.