Pool Perfect with Phos Free

[PoolOwnerNumber9]

Originally from this thread, moved to The Deep End. JasonLion

Pool Perfect with Phos Free contains Lanthanum chloride and Lanthanum sulfate. Lanthanum is a silvery white metallic element. The metal reacts directly with elemental carbon, nitrogen, boron, selenium, silicon, phosphorus, sulfur, and with halogens.
As it reacts with the phosphate, the insoluble lanthanum phosphate precipitates out as a very fine white compound. The particles formed are too small to be removed with a conventional filter, and often require significant effort to remove. Further, if an excess of the compound is added, various side reactions may occur, including the formation of other precipitates that are similarly distributed throughout the pool, and difficult to remove. You can floc if necessary and then vacuum to waste.
Municipal water suppliers are using phosphates to help control corrosion in water pipelines. Their use of orthophosphates causes the most problems. Most available phosphate test kits measure the element in parts per billion (ppb). But make sure you have a test kit that measures orthophosphate, as it is the only form of phosphate algae can digest. The level of orthophosphate should be no higher than 125 ppb. Once levels get up above 200ppb, the likelihood of algae developing becomes much greater. More phosphate means the algae will be more resistant to typical treatments. Once your phosphates are under control, discontinue use of the Phos Free. Use a good Poly 60 algaecide on a regular basis to control algae.
You need to be careful that your cell does not become clogged. Check it regularly. It is important to avoid putting any chemicals through your skimmer while the cell is in-line.

 

[chem geek]

Re: Raising calcium level question

PoolOwnerNumber9,

You can keep algae from growing by maintaining a high enough Free Chlorine (FC) level relative to the Cyanuric Acid (CYA) level or you can use a phosphate remover to eliminate an essential nutrient or you can use an algaecide such as copper. You can also inhibit algae growth via PolyQuat algaecide or by Borates. There are many options, but for simplicity and least expense and the least side effects (such as staining from copper), chlorine is what is recommended on this forum (plus Borates for other purposes as well).

I have somewhere between 2000 and 3000 ppb orthophosphates in my own pool yet keep algae from growing by maintaining proper chlorine levels. I don't use any additional algaecide or phosphate removers -- only chlorinating liquid. My water supply has from 300 to 500 ppb phosphates intentionally added (by my water supplier) as zinc phosphate to prevent corrosion.

Why do you promote using a phosphate remover until phosphates are under control and then using Poly 60 algaecide? Though these are certainly alternatives, they are not the only approach and chlorine alone can prevent algae in almost all circumstances. Only in extreme cases of extraordinarily high phosphates (>> 3000 ppb) or more resistant algae (yellow/mustard algae) are other methods sometimes necessary. There is nothing wrong with someone using these other methods if they WANT to as they are effective, but they do not HAVE to as chlorine alone is a reasonable option.

Richard

 

[Guest]

I repeat this with empahsis:
Right from the Natural Chemistry website on the Pool Perfect with Phos Free page (and on several other of their pages) is this disclaimer:
'Normal sanitizer levels will prevent algae growth. Maintain dealer recommended sanitizer levels in accord with your sanitizing system.'
http://naturalchemistry.com/pool-and-sp ... cts/show/6

I think that says it all!

 

[JasonLion]

Low phosphate levels can help to suppress algae, since algae requires phosphates to grow. However, maintaining appropriate FC levels, even with very high phosphate levels, will also suppress algae with less effort and at a lower cost. Given the effort and expense of removing phosphates, particularly in areas where there are phosphates in the fill water (which is getting more common), there doesn't seem to be much point in removing phosphates except as a last resort.

 

[PoolOwnerNumber9]

My comments about Phos-free were only in response to the original poster’s questions about the white flakes, and what Phos-free was used for and general guidelines for use. I was not promoting it. I think that it can be helpful in a limited number of cases. This quote from Natural Chemistry: “'Normal sanitizer levels will prevent algae growth” means that “high” levels of chlorine become unnecessary when you have very low phosphates.

In your shock charts you show a recommended target free chlorine of 9 ppm and a shock level of 30 ppm at a Cyanuric acid level of 80. I feel that those are fairly high chlorine levels. I think that people should monitor their phosphate levels and consider addressing high levels (500ppb -1 ppm +) as one option based on their particular circumstances.

I do not necessarily recommend that most people need, or even should be concerned about lower levels of phosphates. Removing phosphate can be unnecessarily expensive, and cause other problems as well. I do like to use and recommend the minimum maintenance dose of Poly 60 algaecide for many pools.

 

[chem geek]

I know that it may be hard to believe, but 9 ppm FC with 80 ppm CYA has the same hypochlorous acid (i.e. "active" chlorine) concentration as 3.5 ppm FC with 30 ppm CYA. Both sets of water will oxidize swimsuits at the same rate, cause hair to frizz and skin to flake at the same rate (which is very low), corrode metal at the same rate (also low), kill bacteria at the same rate and kill or prevent algae growth at the same rate and have about the same ORP reading. The only difference with the higher FC level at higher CYA levels is if you drink the water in which case you get more total chlorine ingested. The higher CYA level also protects chlorine loss from sunlight so even at the higher FC level there is less absolute FC loss (an expected result we have confirmed with experiment and real user cases).

An indoor pool with 2 ppm FC and no CYA, for example, has almost 20 times the concentration of hypochlorous acid. It is far, far stronger in oxidizing and killing power -- too much so. This is why after just one winter season in an indoor community pool with 2 ppm FC and no CYA that my wife's swimsuits degrade (elasticity gets shot), her skin is flakier and hair frizzier (she has to use special shampoos). In our own outdoor pool with around 3-5 ppm FC and 30 ppm CYA, the same (duplicate) swimsuits have lasted for nearly 5 seasons and her hair and skin have much less noticeable effects. I also believe the lack of CYA use in indoor pools is part of the reason they have so many more problems with disinfection by-products that can trigger asthma and other respiratory problems as well as ocular issues (though of course, air circulation and lack of sunlight are also factors -- but 20 times the "active" chlorine concentration certainly plays a role for nitrogen trichloride production from ammonia breakpoint though we still need to learn what really happens with chlorine oxidation of urea).

I know that the industry doesn't talk about the chlorine/CYA relationship, but it's absolute hard-core science known since at least 1974. Roughly speaking, it is the ratio of FC to CYA that determines the concentration of "active" chlorine (hypochlorous acid). More technical info about why this ratio works is in this post.

Richard