- May 10, 2013
- 6
writingwizard said:We use the Taylor test kit, and we also use a photometer. Daily bather load is approximately 120 people. We also do a daily 10 minute backwash to help combat the high bather load. We have read that backwashing 8 gallons of water per bather, on a daily basis will help to combat the CC. We don't use Cyanuric acid, since we are an indoor pool. (We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.
How old is the water? Tds is getting high but shouldn't be causing reactions. If your using an enzyme treatment and your water is set at 92 be weary and verify your enzyme capacity. Most enzymes are sluggish to work outside the operating temps. At my store we have one designed for spas and one for pools. I had a commercial customer who had problems but your already using a non chlorine shock. If your having problems though, you can use the mps more then once, especially in warmer water I have a customer who uses it dailywritingwizard said:Hi there,
We operate a small, indoor, commercial pool, and we are struggling with bathers who complain of skin irritation and itching after prolonged exposure to the water. We use liquid sodium hypochlorite that is injected automatically by our Prominent Fluid Injection System. The fluid injection system also automatically regulates our pH by injecting muriatic acid. (We also manually test the water 3 times per day.) We do not use any cyanuric acid in our pool. We also do a daily enzyme treatment on the water using the Orenda enzymes. We have a high rate sand filter, and a 2 horsepower pump. Our free chlorine is consistently at 1.5 ppm, and our pH is kept at 7.4. Our combined chlorine is usually between .2 and .7. We do a weekly non-chlorine shock, using potassium monopersulfate. Our TDS is currently at 1300. Our pool is kept at 92 degrees, and we do have a high bather load.
Any ideas what could be causing the itching/irritation for our bathers? We are trying to be proactice with our pool maintenance, yet even when our numbers seem to be in range, it still seems that our water causes irritation. Any input is appreciated.
Why don't you tell whomever in your city is making this ridiculous recommendation that this paper which is probably the one that got them all in a tizzy is about melamine and cynauric acid combined. It is not about Cyanuric Acid by itself. CYA has been extensively tested for toxicity and you can read details in this report where it shows that CYA has lower toxicity than ordinary table salt (lethal dose is 7700 mg/kg compared to ordinary sodium chloride table salt at 3000 mg/kg -- lower numbers are more toxic) and has minimal dermal absorption. As for toxicity to reproduction, the No Observed Adverse Effect Limit (NOAEL) for rats is 600 mg/kg/day while for developmental toxicity/teratogenicity the NOAEL in rabbits is 200 mg/kg/day. A 50 kg (110 pound) female would have to drink 100 liters of 100 ppm CYA water every day to get to the lower of these limits and those are NOAEL so you'd still have no observed adverse effects. In other words, there is no risk for causing birth defects.writingwizard said:(We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.
As others have mentioned, where did you hear that? The Pool Store?writingwizard said:We use the Taylor test kit, and we also use a photometer. Daily bather load is approximately 120 people. We also do a daily 10 minute backwash to help combat the high bather load. We have read that backwashing 8 gallons of water per bather, on a daily basis will help to combat the CC. We don't use Cyanuric acid, since we are an indoor pool. (We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.
Emphasis added. http://www.leg.state.nv.us/nac/nac-444.htmlNAC?444.148??Quality of water. (NRS 439.200, 444.070)
1.??Water entering a public bathing or swimming facility for the first time must meet the bacteriological standards for potable water set forth in the primary drinking water standards adopted pursuant to NRS 445A.855, except the health authority may approve the use of water from natural sources including saline water. Fresh water must be added to pools that depend upon the flow of a stream, lake, well or other source which has been diverted to flow in and out of the pool, at a rate of not less than 1,000 gallons (378.5 liters) per hour for each 20 bathers using the pool during each hour.
2.??All public bathing or swimming facilities must have a uniform flow-through of water in the volume and quality described in subsection 1, or recirculation and filtration equipment provided for water purification in accordance with the requirements of NAC 444.010 to 444.306, inclusive.
3.??The equipment must provide water which meets the following standards:
(a)?The water must be continuously disinfected by a chemical which imparts an easily measured, freely available residual effect. Except as otherwise provided in NAC 444.207, adequate disinfection must be accomplished by one of the following:
(1)?Normal chlorination of 1.0 to 5.0 ppm chlorine at pH 7.0 to 8.0;
(2)?Chlorinated cyanurate chlorination of 1.0 to 5.0 ppm at pH 7.2 to 8.0; or
(3)?Normal bromination of 3.0 to 5.0 ppm at pH 7.0 to 8.0.
(b)?The health authority may accept other disinfecting materials or methods if they have been adequately demonstrated to provide a satisfactory residual effect which is easily measured, and otherwise to be equally as effective under conditions of use as the chlorine concentration required in this section.
(c)?The maximum permissible concentration of cyanuric acid is 100 ppm.
(d)?The total alkalinity should be within the range of 80 to 120 ppm.
4.??The chemical quality of water used in the facility must not cause irritation to the eyes or skin of the bathers, or have other objectionable physiological effects on bathers.
5.??The water must have sufficient clarity at all times so that the pattern of the main drain in any pool is clearly visible from the walk at the deep end. Failure to meet this requirement constitutes a ground for the immediate closing of the facility.
[Bd. of Health, Public Bathing Places Reg. Art. 20 §§ 20.1-20.5, eff. 5-21-74]—(NAC A 7-23-82; 11-1-88)
writingwizard said:Thanks for the feedback everyone. We are in Southern Nevada. CYA is not banned yet here, but it soon will be. Several lawsuits have been won against casinos here that had CYA in their pools. The legislation to ban it has not been passed yet, but it soon will be, most likely. It is already banned in commercial pools in the state of New York, and there are other states that are working to ban it as well or to place a limit on the amount of CYA that is acceptable. This is due to it causing birth defects and also due to it causing the chlorine to become ineffective against crypto.
In the mean time, I will consider your argument for the buffering effect of CYA on our FC. Thanks for your input.
Reference cited for study:Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized.
http://www.iwaponline.com/jwh/004/0425/0040425.pdf
http://libra.msra.cn/Publication/644830 ... ilot-study
CYA reduces the active chlorine level so does make it less effective against Crypto, but normal FC levels without CYA are also ineffective against Crypto anyway. Chlorine alone won't kill Crypto quickly at all. The CT value is 15,300 (see this CDC link) so 1 ppm FC would take 10 days for a 99.9% kill of Crypto. If you wanted to hyperchlorinate to 10 ppm FC, then with CYA in the water you'd have to raise the FC to around 10 ppm higher than the CYA level so at higher CYA levels that can become impractical.Brushpup said:Cya does NOT make Chlorine ineffective against Crypto. It would be a a lack of enough FC to allow it to live.