Ozone.......

[Vinny]

I'm glad you two were able to speak. He was looking to hook up with a microbiologist to learn more.

I responded to a hot tub question at that pool site, responded as I do here and got blasted by the resident geniuses. Their interpertations of material they led me to was much different than mine and they would pooh pooh anything I said off and then couldn't answer my questions other than saying "because" (my interpetation).  I am not a "because" type of person.

He chimed in and explained some things. He also led me to studies (I may have read them in the past) about bacteria, cysts and such along with chlorine/CYA studies.  Other than the possible harmful human effects soaking in 100+ PPM CYA (1 month tub water) "normal"  bacteria is still being killed even at 300+ PPM CYA (3 month water) - before he stepped in was a "thou shall not use dichlor" discussion ... of course I'm sure the ones that were saying that never read his posts to me. I respect him enough to have finished that conversation but because of the attitude of others there I don't intend to post there again.

Just one bit of info about CYA if you didn't discuss it with him - CYA buffers the corrosive effects of chlorine so if you intend to add chlorine (not using dichlor) for the study it could cause corrosion issues if you plan on testing for a long period of time. 20 PPM CYA will buffer to about 4 PPM chlorine.

One last question if you don't mind ... His concern about soaking in water without chlorine was the fecal (or it could be rectal) to oral contamination. My thoughts after he mentioned it were that it would take 20 minutes for x number of bacteria to double and another 20 minutes for the 2x bacteria to double - at this point (maybe sooner) chlorine would be introduced and the bacteria will hopefully be killed. Is this type of contamination really a concern during use?

Thanks!

Vinny

[In Canada eh]

Hi ICe (appropriate acronym for your neck of the woods)!

Regarding the UV wavelength, most in the DW treatment industry are familiar with the 254 version and it is highly effective in microbial control; the 185 nm UV is less well known, so you have a lot of company in not having been familiar with it.  The UV185 is often used in ultrapure water (UPW) applications; it's effectiveness on TOC reduction is well documented.

Regarding Chloramines...in the US there continues to be a movement toward their use vs. traditional chlorine; principally to reduce formation of Disinfection ByProducts (DBF).  It certainly accomplishes that but there are adverse effects reported - some health / aesthetic effects suchs as skin irritation, eye irritation, etc. others from a microbial control standpoint.  We were involved in a fairly extensive study on a Florida water system that had switched to chloramines and started having positive coliform results in the distribution system.  I think this is a debate that will go on for some time.

Vermonter

Vermonter

   Using the assumption that you are from Vermont,  I'm south of you so its you guys that the ICe acronym applies to  

  One of the reasons we started to use chloramination was to combat positive coliform tests in the distribution system, too date it appears to have been very successful.  I wonder if your Florida study issues are due to water temperature