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Post by biomedfossil on Jan 7, 2022 14:53:13 GMT
I was wondering if anyone can answer a question for me? I work with Fresenius and was disinfecting my Aqua B Ro last night with minnecare. The minnecare residual strip showed 0ppm at all ports so I loaded up and went home. This morning I received a call and the RPC strips was showing .2ppm. The RPC shows 0ppm coming into the Ro. So I know the water is good. There must have been traces of minnecare left which is causing a false positive. I have never had this happen before. So I don't know if there is something going on with my Ro or what's causing it. I can't just let them start dialyzing if the strip reading to high. So is there a different strip Fresenius uses to weed out the chemical reaction by chance? Has any one else come across this and is there a way to keep it from happening again. Thanks for your knowledge..
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joey
Full Member
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Post by joey on Jan 7, 2022 15:09:05 GMT
I was wondering if anyone can answer a question for me? I work with Fresenius and was disinfecting my Aqua B Ro last night with minnecare. The minnecare residual strip showed 0ppm at all ports so I loaded up and went home. This morning I received a call and the RPC strips was showing .2ppm. The RPC shows 0ppm coming into the Ro. So I know the water is good. There must have been traces of minnecare left which is causing a false positive. I have never had this happen before. So I don't know if there is something going on with my Ro or what's causing it. I can't just let them start dialyzing if the strip reading to high. So is there a different strip Fresenius uses to weed out the chemical reaction by chance? Has any one else come across this and is there a way to keep it from happening again. Thanks for your knowledge..
Are you turning off your RO when it is clear, letting it sit for 5 minutes, then running it for 5 minutes, then repeating those two steps to clear the rebound residual?
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Post by gnurk on Jan 7, 2022 15:29:46 GMT
also when done rinsing ro run all machines thru a rinse and check for minncare at drain
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Post by Guesttoday on Jan 10, 2022 19:14:22 GMT
Sounds like rebound residuals left in the loop. Air pockets could have been created during disinfect procedure. Marcor does not have any other type of residuals test strips for checking minncare as far as I'm aware. As the guys posted above, its a good and important practice to turn off the RO/RO pump for 5-10 minutes and then turning them back on to check for residuals. Machines should be rinsing as well as being checked for residuals as drain. If you have endotoxin filters with valves (top/bottom or both), you should open those and burp the top valves.
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Post by anon’s face on Jan 10, 2022 21:45:47 GMT
Sounds like rebound residuals left in the loop. Air pockets could have been created during disinfect procedure. Marcor does not have any other type of residuals test strips for checking minncare as far as I'm aware. As the guys posted above, its a good and important practice to turn off the RO/RO pump for 5-10 minutes and then turning them back on to check for residuals. Machines should be rinsing as well as being checked for residuals as drain. If you have endotoxin filters with valves (top/bottom or both), you should open those and burp the top valves. Had this happen twice on one specific Aqua and not on my other 2. It wasnt residual in the loop, it’s giving residual from the RO sample port. We’ve done as the poster above suggested: following the third rinse the RO is left to sit 5-10 mins, followed by a rinse. If still positive, another rinse. Repeat. However, this wasn’t a check before, we were only using Residual Minncare strips. |
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Post by jaretac on Jan 22, 2022 15:09:33 GMT
I was wondering if anyone can answer a question for me? I work with Fresenius and was disinfecting my Aqua B Ro last night with minnecare. The minnecare residual strip showed 0ppm at all ports so I loaded up and went home. This morning I received a call and the RPC strips was showing .2ppm. The RPC shows 0ppm coming into the Ro. So I know the water is good. There must have been traces of minnecare left which is causing a false positive. I have never had this happen before. So I don't know if there is something going on with my Ro or what's causing it. I can't just let them start dialyzing if the strip reading to high. So is there a different strip Fresenius uses to weed out the chemical reaction by chance? Has any one else come across this and is there a way to keep it from happening again. Thanks for your knowledge..
It is for sure rebound because RPC will react to Minncare presence. I have an Aqua B at one of my clinics and haven't had this issue...yet, but I have seen this on a CWP and of course have had rebound in indirect systems. First thing to do is to make sure you are doing the disinfection correctly from start to finish. One thing about the Aqua B is you must go to class before you can preform the disinfection. Second, what is your ring length and do you have the proper levels of Minncare. Third, all machines and mixers are disconnected from the fly loops before initiating disinfect. When the RO goes into dwell you should be testing for presence at every fly loop and port in the loop. After the first rinse I start checking at the loop return, once that is clear than I start checking all the other ports starting at RO1 and following the loop in order. I always rinse my loop twice and I have a short loop with just 15 connections. If you have a longer loop you may need more rinses. A couple of other notes, Is the RO setup to rinse itself when turned off? I have mine setup to start a rinse a half hour before first tech arrives every morning. Also then I have the techs put all machines through a full rinse before taking readings. Again they do this every morning regardless of disinfect. Regardless of what Marcor might tell you (because they will tell you it's safe), you are correct that you can not start treatments as long as the RPC strip reads high. |
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Post by Bruce Fife (RPC) on Jan 28, 2022 20:01:38 GMT
The scenario described in this thread (i.e. post RO use of the RPC Ultra-LowTM Total Chlorine Test Strips, K100-0118 or K100-0118/F) assumes that the residual level of peroxyacetic acid (i.e. PAA, Micro-X, Minncare) is truly at zero ppm. However, it’s highly likely that there are still trace amounts in your sample. Because peroxide is at a much larger concentration (approximately 5X) than the peracetic acid in the peroxyacetic acid disinfecting solution, the typical PAA residual test strip tests for the absence of hydrogen peroxide in the disinfecting solution. Because the lowest color value on a typical PAA residual test strip is 1 ppm, the strip sensitivity limit will normally result in a zero color at residual amounts below 0.25 to 0.5 ppm. This amount of residual peroxide (oxidizer) will cause an interference reaction on the necessarily very sensitive (0.01ppm) RPC Ultra-Low Total Chlorine Test Strips (K100-0118, K100-0118/F). Additional rinse time may be necessary to reduce the PAA (peroxide) residual amount such that it does not interfere with the Ultra-Low Total Chorine Test.
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Post by Chuck Weddle on Jan 28, 2022 21:40:59 GMT
The scenario described in this thread (i.e. post RO use of the RPC Ultra-Low TM Total Chlorine Test Strips, K100-0118 or K100-0118/F) assumes that the residual level of peroxyacetic acid (i.e. PAA, Micro-X, Minncare) is truly at zero ppm. However, it’s highly likely that there are still trace amounts in your sample. Because peroxide is at a much larger concentration (approximately 5X) than the peracetic acid in the peroxyacetic acid disinfecting solution, the typical PAA residual test strip tests for the absence of hydrogen peroxide in the disinfecting solution. Because the lowest color value on a typical PAA residual test strip is 1 ppm, the strip sensitivity limit will normally result in a zero color at residual amounts below 0.25 to 0.5 ppm. This amount of residual peroxide (oxidizer) will cause an interference reaction on the necessarily very sensitive (0.01ppm) RPC Ultra-Low Total Chlorine Test Strips (K100-0118, K100-0118/F). Additional rinse time may be necessary to reduce the PAA (peroxide) residual amount such that it does not interfere with the Ultra-Low Total Chorine Test. Bruce, I think you may have misread the post. My take is the poster was referring to the Micro-X Peroxide / Peracetic Acid Residual Test Strips K100-0100 strips, not the Ultra-Low Chlorine Test Strips K100-0118. |
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Post by Bruce Fife (RPC) on Jan 28, 2022 23:22:51 GMT
Thanks Chuck. The reference to 0.2 ppm in the original post refers to the K100-0118 test strip since it's the only strip with that color block reading. In other situations I've encountered, they use both strips to confirm negative readings post disinfection.
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Post by Bruce Fife (RPC) on Jan 29, 2022 1:00:27 GMT
One more point of clarification; both these test strips are used to detect different residuals. The K100-0118 test strip is used to test very low levels of chlorine and chloramines (TC) in water, while the K100-0100 is used to test residual Peroxyacetic Acid after water system disinfection.
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Post by Chuck Weddle on Jan 29, 2022 11:28:03 GMT
Thank you, Bruce. I was the one who misread the post.
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joey
Full Member
Posts: 200
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Post by joey on Jan 31, 2022 12:51:11 GMT
A similar thing happened when I used the IBT chlorine/peroxide test strips. The strip reads a very light blue for what seems like forever but my minncare residual strips read absolutely white.
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Post by biofossil on Jan 31, 2022 18:27:07 GMT
Sorry I haven't been on in a while. What I have done since this post is once my resdiual strip is clear. I turn on every piece of equipment on the loop and let everything run for appx 30min. This seems to be enough time to clear the loop completly. So far I haven't had any other problems since I started this routine. To answer some of the questions. I have a short loop (12 stations), The Ro does rinse through out the night every 2 hours, the staff do rinse machines every morning and the rinse program is set to 950l. I run it through at lease 2 complete rinse cycles each time. I still don't understand what has changed on the Ro. I never had any problems clearing out the minnecare until recently. All of my readings on the Ro haven't changed. I will continue to monitor it and hope the problem doesn't reoccur. Thank you for all your input..
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