Will water softener remove CYA?

[PoolOwnerNumber9]

Does anyone know if a water softener will remove Cyanuric acid? I have never tried it. I have always just drained and refilled. Once, I had two neighbors, one with high CYA and one with low CYA; I balanced both by exchanging the water for each until they were equal, but that was a rare opportunity.

I have called a few Water Softener Companies, but they all seemed stumped by the question. There are some water treatments that can remove cyanuric, but they would be cost prohibitive. A water softener would probably not be economical for most situations if it would work.

 

[SeanB]

Re: cya too high

Are you confusing Calcium Hardness with Cyanuric Acid?

 

[JasonLion]

Re: cya too high

No, a water softener won't remove CYA.

 

[PoolOwnerNumber9]

Re: cya too high

I did mean Cyanuric acid. I was just wondering if a water softener would work if there was a situation where draining and refilling would, for some reason, be very difficult or costly. I'm sure that there is a way to remove Cyanuric Acid, but nothing that would be affordable.

What would remove cyanuric if someone had to? And, why won't a softener do it?

Could you use a reverse osmosis system or a distillation process of some kind?

 

[SeanB]

Re: cya too high

You have to drain and refill with fresh water to lower cya. It may weather off a bit on a closed pool, but draining and refilling is the only proven and reliable way to lower cya. I believe there is a product that can remove cya but it's a lot more expensive than just draining and refilling.

There is no mechanical means to lower cya.

 

[JasonLion]

Re: cya too high

There used to be a cyanuric acid reducer product. But it doesn't seem to be available any more. It was quite expensive for real world usage (it didn't seem to reduce CYA nearly as much as it claimed) and tended to make the water cloudy for days.

We believe that it worked on the same principal as the CYA test, melamine would react with the cyanuric acid causing it to precipitate.

 

[ivyleager]

Re: cya too high

One way to lower your CYA is to actually let the pool get algae. There's been mention of this phenomenon occuring one time or another on this forum before.

 

[frustratedpoolmom]

Re: cya too high

One way to lower your CYA is to actually let the pool get algae. There's been mention of this phenomenon occuring one time or another on this forum before.

Slightly incorrect. According to a post earlier this week by Waterbear:

It is not algae that eat CYA but anerobic (oxygen hating) bacteria that are usually found in soil. Unless the pool was totally stagnant with no circulation or sunlight then that is NOT where your CYA went.

I don't think allowing a pool to get algae is a good recommendation for lowering CYA. Plenty of posters on here with green water and/or black algae reporting simultaneously lots of CYA.

Partial fresh water replacement. That's about it.

 

[SeanB]

Re: cya too high

One way to lower your CYA is to actually let the pool get algae. There's been mention of this phenomenon occuring one time or another on this forum before.

Let's stick to proven techniques rather than trying to replicate "phenomenons."

 

[Guest]

Re: Will water softner remove CYA?

Getting back to the OP's question, no a water softener will no remove CYA because the ion exchange resin used in water softeners only replaces cations in the water like calcium, magnesium, and other positively charged ions with sodium ions. It has no effect on anions (negatively charges ions) such as cyanurate ions.

 

[PoolOwnerNumber9]

Waterbear, the anion cation question was one of the things that the water softener company was unsure of. They did say that there was a system to exchange anions instead of cations. Do you think that would work?

 

[Guest]

Waterbear, the anion cation question was one of the things that the water softener company was unsure of. They did say that there was a system to exchange anions instead of cations. Do you think that would work?

There are ion exchange resins that will remove anions BUT the question remains as to whether they are effective at removing cyanurates, what anion the resin is putting in the water to replace the revomed ones, what other anions will be removed from the water (chlorine comes to mind) and the amount of resin needed to process the water in the pool. The problem with most residential water softeners is that they do not have the capacity to process the amount of water in a swimming pool without being regenerated.
The final question becomes is this cost effective. I believe that if it were a viable and cost effective solution it would have been implimented already. Draining and refilling might not be the most convenient way to lower CYA but it is an effective and cost effective way when compared to the alternatives (such as precipitation with melamine).

 

[PoolOwnerNumber9]

Water can be totally deionized by using a resin that replaces cations with hydrogen and anions with hydroxide. With this type of resin, the cations stick to the resin and the hydrogen and hydroxide that are released combine to form pure water. Deionized water which is also known as demineralized water (DI water or de-ionized water; also spelled deionized water) is water that has had its mineral ions removed, such as cations from sodium, calcium, iron, copper and anions such as chloride and bromide. Deionization is a physical process which uses specially-manufactured ion exchange resins which bind to and filter out the mineral salts from water. Because the majority of water impurities are dissolved salts, deionization produces a high purity water that is generally similar to distilled water, and this process is quick and without scale buildup. However, deionization does not significantly remove uncharged organic molecules, viruses or bacteria, except by incidental trapping in the resin. Specially made strong base anion resins can remove Gram-negative bacteria. Deionization can be done continuously and inexpensively using electrodeionization.So, it looks like a deionizer would work. Cyanuric acid is an organic molecule. The only issue is, are we sure that it is actually charged? Also, just because something has never been done does not mean that it will never be a viable solution in the future. I would say that if it was done it would have to be a system that could do the entire pool in a relatively short time so that once all of the ions are removed you could rebalance the water as soon as possible.

 

[Guest]

Water can be totally deionized by using a resin that replaces cations with hydrogen and anions with hydroxide. With this type of resin, the cations stick to the resin and the hydrogen and hydroxide that are released combine to form pure water. .

The problem with these type of 2 column or 4 column units (and I have worked with them) is their cost and capacity. Once again they are not going to be a viable alternative for a 15K swimming pool.
CYA in the water will form cyanurate ions but also chlorinated cyanurates when chlorine is present so ion exchange may not be viable anyway.

Also, this topic has become more suitable for "the deep end" so I am moving it there.

 

[chem geek]

Since this topic is in the deep end now, I'll add that the primary species at the pH of pool water is singly negatively charged cyanurate ion H₂CY^- (where H₃CY represents Cyanuric Acid as a shorthand formula). For the chlorinated isocyanurates, the dominant species is HClCY^-. Of course, any sort of deionizer is going to be removing a lot of other substances such as components of salt (sodium and calcium for positive ions; chloride for negative ions) so unless there is a SELECTIVE ion exchange system that strongly binds to cyanurate ion, I don't think it's practical at all.

Richard