Cationic Polymer - Pool Clarifier from HTH -Questions

A few questions.

Does anyone know if this pool clarifier contains phosphates?

HTH hotline states that it contains only a Cationic Polymer, what is a Cationic Polymer?

Has anyone tried it and is it good for removing metals?

Found it at Wal-Mart and it seems inexpensive, although I cannot remember the price.

Found this link (not for same product) for those you who know how to decipher it,

http://www.accepta.com/prod_docs/209...lymer%20%22%22

and here,

http://www.cob.org/pw/water.htm

Seems as if this might be good stuff, or is there a downside?

Looking forward to your replies.

Aloha.

HTH used to list the ingredient as sodium polyacrylate but now just say cationic polymer. Don't know if they changed the forumula or not. Sodium polyacrylate is the same stuff that Clorox puts into their 'new and improved whitening formua' bleach that has gotten much discussion on the forum in the past. Sodium polyacrylate is a cationic polymer (there are many chemicals that are in this general group) which means it is a long chained molecule with a postive electrostatic charge (cations are postively charged and anions are negatively charged) and will bind with particles in the water that have a negative charge. This is how it works to clarify the water. The negative particles clump together on the polymer and are now big enough to be filtered out faster.

There is a downside to using polymeric clarifiers, however. If you overdose they will actually cause the water to cloud and no amount of filtering will remove the cloudiness. This is because an overdose causes the particles to go into a 'colloidial' state. This means they form very small, dispersed particles in the water that are too small to filter because the polymer is now acting like an emulsifying agent. For an example to explain what I mean let's look at mayonaise, which is basically just oil, water,, vinegar, and egg. If you just mix oil, water, and vinegar it will separate on standing into an oil layer and the water/vinegar layer, even if you mix for hours but when the egg yolk is added it emulsifies the oil and water/vinegar and the oil forms finely dispersed colloidial droplets that do no seperate out from the water/vinegar. They just stay in suspension and you have mayonaise! Much the same thing can happen if you overdose a polymeric clarifier (the particles/polymer become collidial) so if you decide to use one be sure to follow the dosing instructions.

I personally do not think that clarifiers are needed. Some of my customers do say they help with sand filters (but adding DE to your sand filter will probably work much better!)

If you have a cartridge filter the chitosan based clarifers (like SeaKlear) seem to be more effective than the synthetic polymers from the feedback I have received from customers (and from what I have read about them).

If you have a DE filter I personally don't think a clarifier will do much at all but probably won't hurt anything.

Hope this info is helpful.

Edit: Although some clarifiers state on the package that they help remove metals I really don't think they are that effective unless the metal is actually precipitated out of solution as a particulate suspension and not just an ion in the water. (Richard, your thoughts on this would be appreciated) If you have a metal problem then a seqesterant is what you need. If you are concerned about using a phosphonic acid based sequesterant (HEDP) there are some on the market that are based on the chelator EDTA such as NaturalChemisty's Metal Free. I personally don't think the HEDP based sequsterants cause problems unless you are one of the very rare individuals that have a problem of recurring algae from high phospates that can't be controlled in any way except with a phosphate remover.

My understanding is that the clarifier (by itself) won't do anything for metals. I have seen some products that combine a clarifier with a sequestering agent, but that's just having two products mixed together into one. I don't know of any selectively precipitating agent that will allow the filter to remove metals from the water without staining other surfaces. It seems that whatever precipitates the metal has a tendency to deposit it on surfaces as a colored stain and not just keep it as a particle that can get filtered.

So the way metals are handled is to keep them dissolved in the water and that is done with a sequestering agent which is generally a larger molecular ring that can hold the metal (charged ion) within it. I believe the details of this including the two types of such agents has been written up in another post on this board, but such details are not important for this discussion. Eventually, drain/refill will dilute the metals out of the water unless your fill water contains metals in which case you'll have to constantly refresh with sequestering agents or will have to remove the metals (by precipitation) before adding the fill water to the pool (as described in another post).

As for other particles that cause cloudiness, the clarifier will work as Evan described but I found in my own pool that a little patience works just as well. I used to use clarifiers to handle general cloudiness and detergents for oil film (suntan lotion) on the water surface. After learning more on this board I haven't used such products and what I found is that initially one does get some slight cloudiness and/or oil film after heavy bather usage, but that it does eventually all break down and go away, the slight cloudiness after only a day and the oil film usually after only a couple of days. A chlorine shock makes it go away faster, but isn't normally necessary. I have a cartridge filter, but suspect it is one of the modern ones (was installed 3 years ago) that are in between a sand and DE filter in terms of what it can filter (though a sand filter with some DE thrown in is probably better).

Generally speaking, whatever is making your pool water cloudy is likely to be an organic substance and eventually it will breakdown and get oxidized by chlorine or the chlorine will form a chlorinated organic that will breakdown by sunlight. So if one keeps their pool covered and not exposed to sunlight (or if its an indoor pool) then it will be harder to get rid of cloudiness, oil films, and combined chlorine levels in general. In such situations it might make sense to use a non-chlorine shock (potassium monopersulfate, KPMS) since that oxidizes organics quite readily and can be used (expensively) as a weekly or bi-weekly maintenance. In my own pool, I now keep the cover open if the water looks like it still has stuff to breakdown (mostly oil film) or if the combined chlorine is measurable (hardly ever happens) and that seems to do the trick and only takes one or two days.

In your situation, you've killed a lot of algae (apparently) so there is a lot to filter out and that just takes time. I would expect that the pool will be completely clear within a week of good filtration, exposure to sun, and maintained chlorine levels (even normal levels, though higher levels will make the process go faster). If you don't care about spending money, you can use non-chlorine shock or a clarifier, but patience is much cheaper and will limit the amount of chemicals you add to your pool.

Richard

Thank you both for the replies.

I have not bought it, nor will I use it. I will remain a loyal Wal-Mart chlorine customer.

Aloha