teapot said:
Subject: Where did my CYA go? Help with CC.
waterbear said:
Your copper is at the low end for algae control (.3- .6 ppm) and high enough to stain or turn hair green. It means that you have to add seqestrant on a regular basis and be very careful NOT to let your pH rise above about 7.8 EVER. I suspect that your actual copper level is a bit higher than .3 ppm.
If draining is the only way out, let us know and we will start today.
Hi Waterbear, interested in your comment above regarding copper. I have realised there is almost a paranoid belief of the TFP forum about copper staining. Have you any documents/info relating to copper staining and the concentration required to turn hair green or stain liners?
Regards
John
I have seen it happen with copper levels as low as .3 ppm in customers pools time and again. Realize that in the "old days" the idea WAS to stain a pool with copper sulfate to prevent algae growth. The hope was that the staining would be blue and make an even stain on the plaster but what eventually happens over time is the blue copper stain oxidized to the black copper stain that can only really be removed by acid washing.
I also happen to be a licensed Barber and Cosmetologists (since the 70's) and have taught both vocations in the past. I have dealt with more than my share of green hair from copper (I was a colorist in the salons I worked in and owened) and actually know the proper way to eliminate it (much like metal stains are treated in pools) with sodium thiosulfate (chlorine neitralizer) and citric acid (reducing agent). These are the very same chemicals used in pools for these same purposes, btw.
All that being said I will say that copper sulfate is the only product sold as an algaecide that will actually KILL an active algae bloom and not just inhibit it's growth (except for the halogens like chlorine and bromine). The biggest problem with copper is that it is forever once in the water. It can be sequestered but seqesterant break down over time and need to be re added on a regular, often weekly, basis. It only takes one pH spike to stain a pool and pH spikes happen even under the best conditions, particularly when pools are closed.
the first time you use copper it often works great so you are tempted to use it again. This is where problems occur. If you are monitoring copper levels and they drop (and you have not sequestered them) then the copper has come out of the water as stain either somewhere in your pool, plumbing and equipment, or on someones hair. If the copper is still in your pool it can and will redissolve in the water when the pH drops, such as might occur when lowering TA or if you use trichlor for chlorination. I have soon too many pool with copper levels well over 1 ppm strictly from regular ( as instructed on the bottle) use of chelated copper algaecides.
Manufacturers and distributors love copper because coppper sulfate is cheap (VERY high profits), has it's own EPA registration so products they use it in have a registration number, and it works fairly well with just one or two applications so the customer if likely to buy it over and over again.
Customers like it because it's "magic in a bottle". Pour it in and the algae dies in a few days. Staining usually does not happen until so much time has passed that the average pool owner does not equate the stains in their pool to the algaecide that they used when they closed last season.
Pool surfact plays in here too. With plaster pools copper stains can be removed by acid washing. Fiberglass usually stains black and the stains are very difficult to remove in most cases. Vinyl liners that stain are ruined and need to be replaced if you want the stains gone.
Copper stains, period. If the level is high enough to kill algae, it's high enough to stain.
I understand that you use an ionizer. If you are not maintaining at least a 2 ppm chlorine residual you do NOT have sanigtized water. The APVMA has basically outlawed ionizers in Australia as stand alone sanitizers, since they are not. (The first two deal specifically with the Zodiac Nature 2 but if your search their site you will find many other ionizer devices have also been recalled and/or banned.)
http://www.apvma.gov.au/archive/gazette0403p14.shtml
http://www.apvma.gov.au/archive/gazette0406p26.shtml
http://www.apvma.gov.au/media/mr0401.shtml
http://www.apvma.gov.au/qa/poolspa_FAQ_May2005.shtml
The EPA in the US does require a minimum residual fast acting santizer requirement with ionizers and they cannot be sold as 'chlorine free' any moresince CT times for copper and silver are very slow. Yet the minimum level required is too low in most real life cases. Because both copper and silver (and zinc for that matter, which is used in some devices instead of copper) are effective algaecides people are lured into a false sense of security because their water is clear. Clear water is not pathogen free water.