algae scrubbing

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
margaret NJ
Pool Newbie
Pool Newbie
Posts: 7
Joined: Tue 28 Aug, 2007 14:34

algae scrubbing

Postby margaret NJ » Wed 29 Aug, 2007 07:07

As I stated before in another thread:
I have algae and it is hard to scrub off now (first I was able to move
it and it turned to dust). I have been scrubbing and it is a back- breaker, is there a chemical safe enough that I can put in there to dissolve the algae?
Thanks
Margaret NJ


fatybabe
Pool Care Proficient
Pool Care Proficient
Posts: 40
Joined: Tue 28 Aug, 2007 05:26

Postby fatybabe » Wed 29 Aug, 2007 21:22

If you dont want to do this manually or cant fix the problem there are some algeacide treatment that can do the job.

One id recommend but very costly Hydrotech Black Algae Killer ( i cant really recall the name) its of some complex copper molecules combined in a diff way than the usual copper based algeacide's so not only is it more effective it prevents staining as well.
margaret NJ
Pool Newbie
Pool Newbie
Posts: 7
Joined: Tue 28 Aug, 2007 14:34

algae scrubbing

Postby margaret NJ » Thu 06 Sep, 2007 10:38

I actually bought some algacide from Leslies and I put it in the pool on Saturday. On Monday, I did a light scrub because it came off real easy. I also added DE to the filter and I am happy to say, I am algae free now for 3 days. Oh and now I am using BBB method and all numbers are good.

Thank you
Margaret NJ
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Postby chem geek » Thu 06 Sep, 2007 12:24

fatybabe wrote:If you dont want to do this manually or cant fix the problem there are some algeacide treatment that can do the job.

One id recommend but very costly Hydrotech Black Algae Killer ( i cant really recall the name) its of some complex copper molecules combined in a diff way than the usual copper based algeacide's so not only is it more effective it prevents staining as well.

If this is the same as Aquachlor Black Algae Killer as seen in this MSDS file , then this is the same as PolyQuat, not copper.

If it is instead Hydrotech Concentrated Algae Kill II as shown here , then this has an MSDS here and is a combination of a linear (foaming) quat with copper that comes in a chelated complex (see this link ) so keeps the copper level lower to prevent staining (while presumably releasing copper as needed to kill the algae).

Leslie's Black Algae Killer is similar -- a combination of a linear quat with copper plus ethanolamine compounds to help sequester the copper.

Unfortunately, the chelates are organic compounds that will, over time, get oxidized and breakdown from chlorine (possibly helped with sunlight) so copper can get released and stain, depending on the amount of dilution of the water and if the pH of the water goes up (which precipitates metals, mostly as carbonates). It's certainly safer than adding copper alone. Metal sequestrant products have the same problem -- they work for a while and hopefully one dilutes the water before they break down or else you need to add more sequestrant. For example, this patent describes the problem (alkanolamine is a synonym for triethanolamine, TEA) that they propose solving with an additional anionic (negatively charged) polymer. Because the polymer does not contain nitrogen, it is not as readily broken down by chlorine. Anyway, such a polymer isn't used in these algaecides and wouldn't be used in conjunction with a linear quat anyway since the cationic (positively charged) nature of the quat with the anionic (negatively charged) nature of the anionic polymer would likely result in a coagulated mess.

Copper is an effective algaecide, but it doesn't disappear after it does its job so pools that have used copper algaecides (or copper ionization) need to be carefully managed (both in pH and in not adding more copper or by adding more sequestrant) so as not to precipitate copper in the future. Personally, I'd rather not use it. High shock levels of chlorine plus brushing will kill black algae, but in pools with high CYA levels most people don't shock at high enough FC levels to do much good. In Margaret's case, her pool had a CYA level of 100 (or more) as described in this post so would have needed a shock level of 40 ppm FC with the brushing and that's just not very realistic. Lowering the CYA level first through dilution and then shocking would have also worked. At least now with the copper in the water, the minimum FC level of 7.5% of the CYA level (which would be 7.5 ppm in her case) won't be needed to keep away algae. Of course, one could use PolyQuat 60 algaecide weekly to accomplish the same thing and not worry about metal staining or one could lower the CYA level and use chlorine alone to keep away algae.

Richard

Return to “Pool Algae & Green Pool Water”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 1 guest