Exactly, and nitrogeneous compounds are always present in pool. so limiting just orthophosphates is pointless.Brad S said:
High CYA Levels, Shocking, Yellow/Mustard Algae
- Thread starter chem geek
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The first algaecide is a fairly common combination of chelated copper (assuming the organic they refer to is for chelation which it probably is) and a linear quat. The latter can foam, but it's cheap and inhibits algae growth though I didn't know if it would work well for yellow/mustard algae. The main problem with this algaecide is that overdosing can lead to staining and eventually the chelating agent will break down from chlorine releasing the copper so unless there is water dilution, the free copper concentration can rise over time. I suspect that it's the copper that is doing most of the work killing existing algae while the linear quat is more for inhibition of growth.Aquaclear-NZ said:
The second algaecide is very interesting and is a polymer but different than standard PolyQuat. It implies that it doesn't break down as quickly from chlorine so could be a decent alternative to PolyQuat as an algae preventative, though probably not great as an algae killer with an existing bloom (at least not by itself). I've never seen any product with that compound though it is listed in the PAN database here with no registered products. Perhaps it's not available in the U.S. PolyQuat is listed here with over 5000 registered products.
The first algaecide is a fairly common combination of chelated copper (assuming the organic they refer to is for chelation which it probably is) and a linear quat. The latter can foam, but it's cheap and inhibits algae growth though I didn't know if it would work well for yellow/mustard algae. The main problem with this algaecide is that overdosing can lead to staining and eventually the chelating agent will break down from chlorine releasing the copper so unless there is water dilution, the free copper concentration can rise over time. I suspect that it's the copper that is doing most of the work killing existing algae while the linear quat is more for inhibition of growth.chem geek said:
The second algaecide is very interesting and is a polymer but different than standard PolyQuat. It implies that it doesn't break down as quickly from chlorine so could be a decent alternative to PolyQuat as an algae preventative, though probably not great as an algae killer with an existing bloom (at least not by itself). I've never seen any product with that compound though it is listed in the PAN database here with no registered products. Perhaps it's not available in the U.S. PolyQuat is listed here with over 5000 registered products.[/quote:30opc08p]
The first algaecide has worked exceptionally well for me here - and also in the more temperate north queensland area in australia where blackspot is prevanlent - like all copper based algaecides, more is not necessarliy better, and questions should always be asked when people are buying this type of product if they have used any other forms of algaecide to prevent overdose.
The second quat algaecide is fairly new, and im not sure if they are producing this in the usa yet - i can ask the questions for you and organise a couple of sample bottles. I am pretty happily converting to this as quat algaecide of choice as it has been proven many times as an effective algae killer and requires only monthly treatment as a backup algaecide.
Fortunatly a test pool with white marble plaster a good dose of mustard alage and what i would consider Crud filtration has dropped in my lap today, so will give it a personal test over the next week.
I'd be interested in what happens with the PolyQuat. If its instructions for use for existing algae are to first shock with chlorine, then add PolyQuat algaecide, then shock again (perhaps over a period of days), then this might be a reasonable alternative for killing yellow/mustard algae in high CYA pools where one wants to keep the higher CYA level. Though your longer-lasting PolyQuat is one maintenance approach, 50 ppm borates could be another. Let us know the specific instructions for the procedure that you use.
I presume you will do the normal things needed to kill yellow/mustard algae such as get behind light niches, under ladders, put in cleaning nets and poles, etc. since this algae likes to hang out in shady areas.
It sounds like this combination has the least side effects, is of reasonable cost, and achieves the goals I was looking for. Please let us know how it works out. Normally we don't use PolyQuat for killing existing algae, but that's mostly because it takes chlorine anyway and chlorine alone can kill green algae effectively. For yellow/mustard algae at higher CYA levels, one can look at the PolyQuat as a helper to boost the kill level (as well as provide an additional mechanism for such killing) so one can use the lower "green algae" shock levels of chlorine (an FC that is roughly 40% of the CYA level).
By the way, though orthophosphate is most readily taken up by algae, this link implies that small organic phosphates can be taken up over hours to days so slow algae growth would still be possible.
I presume you will do the normal things needed to kill yellow/mustard algae such as get behind light niches, under ladders, put in cleaning nets and poles, etc. since this algae likes to hang out in shady areas.
It sounds like this combination has the least side effects, is of reasonable cost, and achieves the goals I was looking for. Please let us know how it works out. Normally we don't use PolyQuat for killing existing algae, but that's mostly because it takes chlorine anyway and chlorine alone can kill green algae effectively. For yellow/mustard algae at higher CYA levels, one can look at the PolyQuat as a helper to boost the kill level (as well as provide an additional mechanism for such killing) so one can use the lower "green algae" shock levels of chlorine (an FC that is roughly 40% of the CYA level).
By the way, though orthophosphate is most readily taken up by algae, this link implies that small organic phosphates can be taken up over hours to days so slow algae growth would still be possible.
Fotunatley i have been involved with this pool since its construction a few years ago, unnfotunatly in the lighting side only, and not the filtration/hydraulics, which is seriously lacking in a bit of common sense..... much like the future maintenance by a service company. The valet had been to the pool around 2 hours before me and had not mentioned algae to either the owner or his boss, so its safe to assume he was not brushing the pool either.
Fortunatly there is no need to get in behind the lights as the are niche mounted fibre optics, and there are beach areas and no ladders
Treatment started today, cya is at 30ppm (ORP controller present), and chlorine has been added to 30ppm, valet/service person was to be brushing properly today. Long life poly quat to be added in the next day or so, followed up by a repeat shock dose on friday. Intention is to wind the ORP controller up slightly as well.
Phosphate level has not been tested as yet as it is not considered by myself as an effective algaecide, however level will be recorded and reduced as part of the maintenance, along with regular monthly algaecide treatment.
The pool is serviced fotrnightly, and now the service person knows what mustard algae looks like, he will be keeping an eye out for it
more to come, including costs
Fortunatly there is no need to get in behind the lights as the are niche mounted fibre optics, and there are beach areas and no ladders
Treatment started today, cya is at 30ppm (ORP controller present), and chlorine has been added to 30ppm, valet/service person was to be brushing properly today. Long life poly quat to be added in the next day or so, followed up by a repeat shock dose on friday. Intention is to wind the ORP controller up slightly as well.
Phosphate level has not been tested as yet as it is not considered by myself as an effective algaecide, however level will be recorded and reduced as part of the maintenance, along with regular monthly algaecide treatment.
The pool is serviced fotrnightly, and now the service person knows what mustard algae looks like, he will be keeping an eye out for it
more to come, including costs
Yikes! 30 ppm FC with 30 ppm CYA! Well, that pretty much invalidates this test since we know that blasting with high levels of chlorine will kill that algae. What I was looking for was a more traditional shock level of chlorine that has the FC be 40% of the CYA level. Oh well, we'll have to wait and see if this approach works in another situation -- preferably one with a higher CYA where you wouldn't as likely be tempted to go to 80 ppm FC with 80 ppm CYA, for example.
waterbear and I disagree on whether algae can grow without phosphates (i.e. can they grow only with nitrates, carbonates, sunlight, water). I know that the other way around is true -- cyanobacteria can make their own nitrates from nitrogen gas (i.e. they are nitrogen-fixing bacteria), but I thought that all algae needed phosphorous (for ATP, DNA and other chemicals).chem geek said:
However, I hadn't considered what spishex wrote about there being other forms of phosphates that algae can utilize. The phosphate removers will only remove orthophosphate. Perhaps that explains why the phosphate removers don't seem to work in some situations.[/quote:1zethmrd]
If it helps during a mustard algae bloom the water was treated with phosphate remover which didn't work, and polyquat 60 which didn't work (although the poly is for prevention so that was after the fact) The sodium bromide worked but yet it did create a large demand chlorine which was introduced via Tri-Chlor and Cal-Hypo.
Thanks for the info. Was a normal shock level with an FC of 40% of the CYA level done, waiting 24 hours, then adding PolyQuat and then bringing up to shock level again? That's really the combo I'm looking at. PolyQuat by itself or at normal chlorine levels isn't going to cut it for killing existing yellow/mustard algae.
I really don't do things by like exact numbers 
But I would have to say yes, the pool was stabilized to around 40-50 ppm and the FC was raised significantly a few times using 24 oz of Cal-Hypo before and after the poly; 32 oz of the poly was used (overdose) the pool was 10,000 gal. It didn't seem like the poly quat helped at all really. When I use the alg60 out in the field I believe it really shows it's power when the chlorine level drops before I can get to the pool and algae doesn't begin to form. The water gets a little hazy but no sliminess etc. I've basically been using it as a backup if the FC chlorine drops prematurely to stretch out the time you have before a large algae bloom forms. After using the sodium bromide process all the brown gritty yellow algae turned gray-white.
But I would have to say yes, the pool was stabilized to around 40-50 ppm and the FC was raised significantly a few times using 24 oz of Cal-Hypo before and after the poly; 32 oz of the poly was used (overdose) the pool was 10,000 gal. It didn't seem like the poly quat helped at all really. When I use the alg60 out in the field I believe it really shows it's power when the chlorine level drops before I can get to the pool and algae doesn't begin to form. The water gets a little hazy but no sliminess etc. I've basically been using it as a backup if the FC chlorine drops prematurely to stretch out the time you have before a large algae bloom forms. After using the sodium bromide process all the brown gritty yellow algae turned gray-white.