Minimun Phosphate Levels ??

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
hoodfigga
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Minimun Phosphate Levels ??

Postby hoodfigga » Mon 12 Nov, 2007 04:58

Well after trying to clear up a green algae bloom for three weeks I think I have finally succeeded. I had to shock the pool twice. Placed a phosphate remover in it (PR-3000 orneada) and used SeaKlear algea Remover. All is fine now except my phosphate level is 200ppb. according to the pool store. I have a salt system and they say that 200ppb is not worth a treatment. Should I go ahead and try to lower the levels even further. Thank you....


chem geek
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Phosphates in pool water

Postby chem geek » Mon 12 Nov, 2007 13:23

The short answer is no, you don't have to go further in lowering the phosphate level.

In a saltwater chlorine generator (SWG) pool, the Free Chlorine (FC) level should be at least a minimum of 4.5% of the Cyanuric Acid (CYA) level to keep away algae. A manually dosed chlorine pool usually requires a minimum FC that is 7.5% of the CYA level, but an SWG does superchlorination in the SWG cell and continual dosing that helps lower the chlorine requirement. Do you know what the water chemistry parameters were at the time the algae developed? The recommendation of most SWG manufacturers that an FC of 1-3 with a CYA of 60-80 is wrong and insufficient for keeping away algae (except the 3 ppm FC 60 ppm CYA combo).

You can use a phosphate remover or use PolyQuat 60 algaecide to keep away algae and use a lower chlorine level, but these are not necessary if you maintain the appropriate chlorine level relative to CYA level. Which approach you use is up to you -- both will work (i.e. chlorine alone, but with sufficient FC/CYA ratio vs. using either a phosphate remover or algaecide) -- the amount of chlorine needed to kill bacteria is much lower than that needed to prevent algae growth so the pool is still disinfected even with rather low chlorine levels. The bigger issue is not having enough chlorine capacity, FC, that you run out locally, but 1-2 ppm in a pool is usually sufficient if the CYA is high enough to protect chlorine breakdown from sunlight (60-80 ppm CYA). That is, the SWG manufacturer recommendation is fine for disinfection, but not for algae prevention (unless the 3 ppm FC with 60 ppm CYA combination is used) unless a supplemental algaecide or phosphate remover is used, but the least expensive approach is just to maintain a higher FC level.

There are quite a few pool users whose pools have up to 3000 ppb in phosphates and do not develop algae because they maintain sufficient FC levels relative to the CYA levels. One needs to look at phosphate removers as another alternative, similar to algaecide -- another tool in the arsenal, but not the only approach that is effective.

Also, be careful about what you use to shock the pool. Some products, such as Leslie's Chlor-Brite which is Dichlor or Leslie's Genesis Shock which is Trichlor, add to the CYA level just making chlorine less effective. For every 1 ppm FC added by Dichlor, it adds 0.9 ppm to CYA. For every 1 ppm FC added by Trichlor, it adds 0.6 ppm to CYA. Marketing such products for use as shocking with chlorine is irresponsible at best. Even Leslie's Power Powder Plus should make clear that being Cal-Hypo for every 1 ppm FC it also adds 0.7 ppm to Calcium Hardness (CH), though in percentage terms (since normal CH levels are near 300 ppm for plaster pools) that is usually not a problem unless used regularly. It is usually best to shock with chlorinating liquid (or unscented bleach) though if price were no object then Lithium Hypochlorite would be another alternative as these do not add to CYA nor to CH.

If you don't have one already, get yourself a good test kit, the Taylor K-2006, from Taylor here or from Leslie's here or from poolcenter.com here (careful: not the K-2005 -- make sure it's the K-2006) or the even better TF100 test kit from tftestkits.com here .

Richard
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Phosphates in pool water

Postby hoodfigga » Mon 12 Nov, 2007 20:31

Thank you for your reply. I must say that this forum and your reply has helped me immensely. As far as what my pool chemistry was when the algae started I could not say. Not because I was not checking but only because I have corrected and checked the water so many times that my head is spinning with numbers. My current shock treatments are only done with the super chlorination mode and extended run times on the pool pump. I have not used any other shock method only because I wasn't sure you could add other chlorination products to the pool when using the SWG. From your reply I see you can. From reading the forums and your reply I see now that the higher the CYA, the higher you have to maintain your FC. Am I correct? My present chemistry is a Ph of 7.5 , Alkalinity of 100 , and CYA of 60. Plaster pool in south Florida, 15,000 gal. I personally like to have the chlorine levels on the low side only because I do not like the dry skin feeling from high FC. I also feel that I need to maintain a higher CYA level because of the brutal long hot sunny days in South FL. In summation my plan is the following. Keep the CYA between 60-80 with a 1-2 ppm and use the algaecide. My algaecide of choice for the treatment and prevention is the SeaKlear Algae Prevention & Remover. The maintenance dose is 16oz of product for a 10,000 gal pool every 3 months. The cost is $17.00 for a quart at my local pool store. The seaklear product is a organo complex formula with copper. Yes copper! Oh Oh stains in plaster. I called the manufacturer and they say there product is triple chelated time released and there is almost a 0% chance of staining if the product is used per directions and the pool is balanced. I hope their right. Any suggestions or comments are welcome. On a side note I was using Jacks Magic Purple for metal control per my pool builder but I have decided not to use it because it is phosphate based. Any opinions on metal control with SWG systems would be greatly appreciated. Thank you.
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Phosphates algae and copper

Postby chem geek » Mon 12 Nov, 2007 23:22

Yes, a higher CYA needs a higher FC level to prevent algae if you are using chlorine alone for such prevention. If you use an algaecide or phosphate remover, then you can have a somewhat lower FC. If you maintain an FC level of 4.5% of the CYA level, so around 3 ppm FC with your 60 ppm CYA (absolute minimum of 2.7 ppm FC) then you shouldn't need to use any algaecide nor phosphate remover. This also should not dry out your skin or hair as this is a very low level of disinfecting chlorine. Nevertheless, if you want to run lower at around 1-2 ppm FC and a higher CYA level of around 80 ppm, then that would result in less disinfecting chlorine -- so you'd have to use an algaecide or phosphate remover. PolyQuat 60 algaecide will cost you around $2 per week and will keep away the algae. The phosphate remover may cost about the same in maintenance mode, but is much more expensive to initially get rid of higher phosphate levels.

I would not use the SeaKlear Algae Prevention and Remover product as this is copper sulfate. I don't care how much they chelate it, the chelation will break down over time and even if it didn't, then the copper concentration will be rather low and less effective. If there is enough copper in the water to prevent algae growth, then there is enough to stain if the pH rises and enough to turn blond hair green. If no one using the pool has blond hair and if you are very careful not to have the pH rise (including from shocking with chlorine) then copper could be OK, but with an SWG pool the pH tends to rise so pH control is harder. You are much better off using PolyQuat 60 from any of a number of brands such as GLB Algimycin 600 or BioGuard Algae All 60 (both products have 60% Poly{oxyethylene (dimethyliminio) Ethylene (dimethyliminio) ethylene dichloride} ).

You can use metal sequestrant products including Jack's Magic that are phosphate based because they aren't orthophosphate initially and even if and when they break down to become orthophosphate, phosphates really don't matter very much. If you are using an algaecide or a phosphate remover, it most certainly won't matter unless you get to extremely high levels above 3000 ppb. The use of phosphate removers are the latest way for pool stores to make a buck, but as I've said before they need to be seen in the context as an alternative algaecide and are not needed if you are willing to maintain sufficient chlorine levels. In your case, since you don't mind spending more to have a somewhat lower chlorine level, you can use PolyQuat 60 algaecide or a phosphate remover. I think the former is a better choice, but technically either approach will work.

By the way, with an SWG you probably find that the pH has a tendency to rise. If you lower the TA to 80 or even 70, then you should find it rises less quickly and that you use far less acid to adjust the pH. See this post for how to lower the TA using aeration and acid addition at a lower pH.

Richard
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Phosphates and algae

Postby hoodfigga » Tue 13 Nov, 2007 04:39

Your explanation is very clear. I will look for the PolyQuat 60. Better to be safe than sorry.
Yes you are right about the pH rising. I constantly find myself adding acid to the pool. I will look into the post about lowering the TA.
I will go back to the jacks magic purple. It is easy to find and affordable. Would you have a recommendation for a maintenance dose with the purple stuff. The bottle states weekly, several post state monthly, and the pool builder says every 3 months add one 32oz bottle ???? My pool is 15,000 gal SWG with plaster. Thanks again. A humble thank you to you.
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Phosphates algae and copper

Postby chem geek » Tue 13 Nov, 2007 21:54

You are most welcome. We're all here to help.

Don't use any pool chemical you don't need. So with Jack's Magic to sequester metals, I wouldn't use it in maintenance mode unless you have fill water that is high in metals. It's better to periodically get the water tested for metals or test your fill water for metals and figure out roughly how much sequestrant you need. You don't want to just add more and more if you don't need to -- the same advice is true for most any of the chemicals -- you want enough to be effective as needed, but not more than that.

PolyQuat 60 dosages for pools have been roughly worked out to prevent algae so their maintenance mode is reasonable since it breaks down over time and it mostly gets trapped in the filter with consolidated particles since it is also a clarifier. Phosphate removers also specify a maintenance mode, but here is a case where you really need to see what your phosphate level is over time and only add more remover when you need it -- otherwise you're just spending extra money faster.

Richard
hoodfigga
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Phosphates algae and copper

Postby hoodfigga » Sat 17 Nov, 2007 07:46

In closing I would like to ask one more question and please try not to laugh out loud. After using the pr-3000 (phosphate remover) and the seaklear algea remover / treatment my pool filter pressure went from 12lbs to almost 30lbs. I have cleaned the filter 3 times with a hose and the pressure has lowered to about 25lbs. If I clean the filter thoroughly or replace the filter, am I removing or negating any of the anti-algae / anti-phosphate treatment out of the pool system.
On a side note I found the taylor test kits k-2006 at a great price with low shipping at SPS swimming pool supply company here .
I have not dealt with them before so I will post my experience at a later time.
I thank you again!!
15000GAL / Diamond Brite Classic / Aquarite SWG / 1.5hp Strarite / Hayward C17502 Cartridge Filter / AquaCal 155A Heat Pump /Sunny South Florida
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Phosphates in pool water

Postby chem geek » Sat 17 Nov, 2007 14:20

I don't know the answer to your question as I don't know why the pressure went up. Perhaps the algaecide was like PolyQuat and is a clarifier so algae got consolidated and caught in the filter. If that is the case, you want to clean the filter and remove such dead algae -- otherwise, it will just be something that uses up chlorine trying to break it down.

Thanks for the new source of the K-2006 at a great price. Just keep in mind that the tftestkits(dot)com link is for a kit that has 36% more volume in the reagents so you need to factor that in when doing price comparisons.

Richard
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Phosphates in pool water

Postby mr_clean » Sat 17 Nov, 2007 17:51

After using the pr-3000 (phosphate remover) and the seaklear algea remover / treatment my pool filter pressure went from 12lbs to almost 30lbs. I have cleaned the filter 3 times with a hose and the pressure has lowered to about 25lbs. If I clean the filter thoroughly or replace the filter, am I removing or negating any of the anti-algae / anti-phosphate treatment out of the pool system.


no, as it has been used up fighting the problem you had & this would be why you would need more for the future.
I'm guess you have cartridge filter sense you state you have to spray it off to clean. You can buy new one if in bad shape or buy cleaner you can soak cartridge in which will help deep clean it.
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Postby hoodfigga » Sat 08 Dec, 2007 07:28

Hello all. Happy Holidays. First I would like to say that I received my Taylor 2006 test kit from Iowa Pool and Spa. The test kit was priced very well with a fair shipping price. Best of all the kits are being shipped directly from Taylor Industries. I figure the kits are new and fresh. Just to let you know I am not a employee of the above company. Just sharing my thoughts.

Using a quality test kit is the way to go. No more guessing and its a plus or should I say a must to compare your results to the pool store. I only wish they would make a ph test that had a definite color change like the chlorine. I really have a hard time seeing those shades of color. A word of advice from a newbie pool owner to another newbie. Spend the money and buy the test kits suggested in the forums. Buying the basic test kits leave you guessing. The Taylor instruction manual inside the test kit is very educational as well.

As far as testing the water at the local pool stores I think i hit the jackpot at a mom and pop store. They test water, build pools and provide maintenance as well. Just when I thought I had it all figured out they test my water and give my a Alkalinity result with correction. Here we go again I said to myself. Corrected Alkalinity what the heck. Turns out after some research you should correct your total alkalinity numbers by a percentage of your cya reading to get a true alkalinity number. Am I right. I hope so because I thought my alkalinity was 100 but they corrected it to a much lower number.
So now I need bicarbonate right. Well the gentleman at the pool store hands my this 5 pound hefty freezer bag with this fine white powder inside. My first thought was ScarFace. It turns out they sell most of their products in bulk. Basically they bag up the same products their maintenance guys use on the field and sell it to the public. Quite a savings compared to the commercial containers that they sell at Pinch a Penny or Leslie's. I do have one question about the pool acid they sell. They use sulfuric acid. The container claims it has low odor and fumes, and it does. That muriatic acid got me few times real good right in the lungs. I tried to do some research but I really could not find a reason for using sulfuric acid vs Muriatic acid. Any thoughts??

Now to cleaning the filter. I have seen suggestions in the forum on cleaning the filter with a solution of cascade and water in a extended soak. Well my filter is really huge and we have water restrictions and I could not justify using so much water to soak a filter. The pool store sells filter cleaning solutions in spray bottles so I figured I would make my own. I took a tablespoon of cascade and placed it in a 32oz. spray bottle and mixed it with water and sprayed down the filter. I let it soak for awhile and hosed it off very well. Viola my water pressure went from 30psi to about 11 psi. It dropped so much I removed the filter cartridge and inspected if for a hole or tear. Anyways thats what I did any comments would be appreciated.

Lastly I started using a pool blanket in the winter months trying to collect heat and save some penny's on the heat pump bill. What can I expect as far as chemical water changes. More chlorine , less chlorine, acid, alk, what effect does covering the water have on the pool chemistry. If you have any links please provide them.

Happy Holidays and thank you for your time once again. In closing my eggnog quote of the day.
"What was was and what is is. Today is what it is. Don't worry about the what ifs and live the what is"
15000GAL / Diamond Brite Classic / Aquarite SWG / 1.5hp Strarite / Hayward C17502 Cartridge Filter / AquaCal 155A Heat Pump /Sunny South Florida

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