I'm in Minnesota and have passed my D,C and B water operators test using your math DVDs and watching your videos. I am taking my A test Thursday. I have done 3 Sacramento books and can honestly say that your information is so easy to understand. You are a very valuable person and teacher to the water community. I hope you continue to make videos as I feel I learn better this way. I truly appreciate all that you have done. PLEASE don't stop doing what you do. Thank you so much! Jesse.

@TheWaterSifu

6 жыл бұрын

Congrats on passing your exams and I wish you all the best on your upcoming A! Thank you so much as well, for the kind words about the DVDs and videos. I really appreciate it. I can assure you that I am still very active, despite the fact that I haven't posted here lately. I've actually been spending some of my spare time putting together a group of continuing education classes lately, and plan on doing more of those in the upcoming months.

Thank you. You bring great insight. You time is greatly appreciated.

very well explained! thank you!

Great help. Thanks so much!

Thank you! Very clear explanation

Thank you! this video is very helpful! :)

u made that easy !! i actually get it now thanx water sifu

that was really helpful. thank you

Thanks for sharing this!

Extremely helpful thank you 🙏🏾🙏🏾🙏🏾

@TheWaterSifu

7 жыл бұрын

Thank you!

thank you sooo much

Very interesting video, we in Mexico i´m working on WWTP but cannot find tech as you have

@ankitsr011

6 жыл бұрын

I am want to work with such a project

Thank you for all the informative videos! We have a rule at my district that we cannot take a coliform sample unless the free chlorine residual is above .20 mg/L. Since the bottles have sodium thiosulfate in them, does the free chlorine residual even matter? I had been taught one way but now I'm starting to wonder. Thanks again for all you do! Your videos are so helpful and easy to understand

@TheWaterSifu

5 ай бұрын

That's a fun question. Thanks for it. We do always take a chlorine residual when drawing a sample, but I can't see the thiosulfate "ruining" the result be the reason at all. I think it's just extra helpful information in the case of an actual positive. For one, opposed to what we always hear and see on exams, you can have a residual below a .20 mg/l in a water system. The requirements are actually way more complicated than "a sample can never be below .20 or its a violation". Also, when you do have an actual outbreak, it can totally kill residual in a system. If the sodium thiosulfate made the grab sample mute, how would you test that area of the system?

thanks ..realy thank u

Do you think there is a 4 hour window?

no need for sample dilution :/ ? or is it because treated water?

tks ty

thank you ty

Useful video. Should you be wearing gloves handling potentially pathogenic water samples and shouldn't the sample be opened under a Bunsen or in a fume cabinet to prevent contamination?

@TheWaterSifu

7 жыл бұрын

Hi Connor. You don't need to wear gloves to protect yourself anymore than you need to wear a body suit for pathogens when you swim in a lake or river. When testing we are dealing with either raw water that comes from a stream or lake, or in most instances, already treated water. The only reason to wear gloves would be to prevent against me contaminating the water, not vice versa. You may want to wear gloves for that, but in my experience most don't. That is why we are super careful not to touch it, but even with gloves you would need to take the same cautions not to introduce batcteria. Also, if there ever is a positive, an automatic retest would be done. As for your second question, the simpe answer would be "no".

@teastation9396

Жыл бұрын

@@TheWaterSifu I am particularly interested in learning more about this. To the point where I want to contact IDEXX to get some clarification. TL;DR - Given that coliform group bacteria are EVERYWHERE, is it really acceptable to just assume the exterior of a sample bottle is clean? What precautions should be taken to prevent contamination during the procedure? And, most importantly, what does the accrediting body, regulatory agency, and SOPs have to say about those precautions? Cause... I've looked and it is super hard to find clarification on that detail. Coliform group bacteria are literally in EVERYTHING. They are not exclusively found in the intestines of mammals. It's in your yogurt. It's in your beers. It's on vegetation and on dust particles in the air. I know this from experience professionally and personally. It's why we had to install specialized sample taps at a particularly dusty sampling site. It's why I had to start using hypochlorite instead of StarSan for disinfecting glassware when doing some home brewing. We had a lab once send out a mass email, basically saying "Oopsies" after they had contaminated a batch of agar and sent dozens of systems into TCR violation. Performing these tests has always been a concern of mine because you practically have to collect the sample in a vacuum, wearing a full hazmat suit, having the perfect and perfectly sanitized sample tap in order to have ZERO doubts about contamination from the environment or sampler. Then you are assuming the lab tech didn't accidentally contaminate it during the procedure either. I agree and disagree with the gloves as a result. If your hands are truly sterile, then it wouldn't matter. But gloves might reduce the likelihood because coliform can hide out in your nails and in the wrinkles on your skin. Point taken - short of chlorinating your hands, the best prevention is just to not touch any of the surfaces. Use aseptic procedures. But it doesn't hurt to wash and sanitize your hands and then put on some sterile gloves. What I would really like to know is if IDEXX recommends cleaning the exterior of the bottles before pouring the water into the quantitray for MPN enumeration. Or, as your viewer suggested - at the very least opening under a Bunsen or in a fume hood.

Under the uv, positive of ecoli will be in white and negative will stay yellow...correct? Abit confuse

@TheWaterSifu

5 жыл бұрын

yes

Hello! May I ask for how long is the water sample still valid for testing for MPN after I collect it? Is it still valid if I store them in a sterile bottle for 12 hours or 24 hours? Thank you!

@TheWaterSifu

Жыл бұрын

Hello... depends. Treated water samples from a water system, which are where most samples come from, are good for 30 hours. Raw, source water samples are considerably less... off the top of my head its either 6 or 8 hours. The only other thing I feel a weird need to clarify (because you likely already understand this) is the word "sterile" in your question. Although, the sample should be taken very carefully, so as no to contaminate it, the bottle itself does not have anything in it to sterilize the sample. It actually contains an ingredient to neutralize any chlorine in the sample taken, because contact time with that chlorine might kill any coliform bacteria that might be in the sample when taken.

@pluto5076

Жыл бұрын

@@TheWaterSifu how about those that came from hand pumped deep wells?

@TheWaterSifu

Жыл бұрын

@@pluto5076 Sounds like you are asking for info related to a specific situation you are directly involved in, and I usually try to avoid giving answers to specific situations that I don't have firsthand knowledge of, for liability and other situational reasons. I like to keep my answers to general situations you will see on exams. I would recommend calling your states DPH and they should be able to answer your question directly.

I want to work with you

Hey how are you sir

Excuse me, can i working this method on wastewater ?!

@TheWaterSifu

Жыл бұрын

Not sure my friend. I've never personally worked in wastewater, or tested for any wastewater certs. All my experience is in potable water.

@moha.salah88

Жыл бұрын

thanks

@yem7157

9 ай бұрын

Yes. We use the same indexx system at our wwtp. I will say your positive e.coli will be more of a bluish than white

uhmm.. did i heard it right? you incubate it for 24 hours? is it too much ? the requirement for incubation is only 18 hours until 22 hours ...

@TheWaterSifu

5 жыл бұрын

One of the great things about KZread is that if you are not sure if you heard something right or not, you can always rewind it and listen again. There are many tests we use in water treatment, so you may be used to a different test, but this main test is definitely 95 degrees for 24 hours, and then there is a small window afterward in which you need to read the results. It is actually even a very common question asked on state water treatment or distribution exams, so if you plan on taking any exams soon and you get the question, please answer 24 hours.

@josephhakim6082

2 жыл бұрын

@@TheWaterSifu in the sac state manual it says inspect after 24 and 48 hours is it different based on the reagent used?

@TheWaterSifu

2 жыл бұрын

@@josephhakim6082 Hi Joseph. Without knowing the exact wording of what you are referring to, I cannot reply to it's meaning. Having said that, if i were to blindly just guess... some tests for coliform run an extra 24 hour test when you have a coliform positive to test for ecoli