Another boil advisory

[nereefpat]

Yes, they were indeed. Thank you. The point, however, is still unchanged, and I don't think that we can just say that a solution is always one of those. Doesn't it change depending on what is in the solution? For instance, my house is always 75 degrees but I adjust that number depending on who is coming over for dinner. Even my wife experiences that same temperature differently that I do.

Semantics. The discussion is centered around a bacteria's viability in the RO/DI and in the tank-water. I'm trying to determine if I should do something to my RO/DI unit after this water boil, or not. Keep in mind that it had not been used for a few days prior to the advisory being issued.

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If you Google boil water protocol, every site says to boil water used for drinking, teeth brushing, food prep, etc. They also say it's fine to bathe or shower as long as you don't drink the water get it in your eyes. Many of the sites discuss RO systems, and they are safe if you have a properly working unit.

I would be fine using my RODI for the fish, just my opinion

 

[Airborne12B]

Airborne: There are a lot of scientific inaccuracies on this thread. but since those inaccuracies are irrelevant to your question(s), here's the bottom line:

Your RODI system has bacteria and bacterial spores in it all the time upstream of the RO membrane. And there's a near 100% chance that it has detectable bacteria downstream of the RO membrane in your DI cartridge and tubing as well. This is irrespective of "boil water advisories" from your water department. There is no reason that you cannot use this for your reef tank - I can guarantee you that 100% of us 100% of the time use RODI for water changes and top-offs that have detectable bacteria in it. Those bacteria will not cause an issue. One of the reasons is that your reef tank has several million bacteria per mL under normal operation. Very slightly adding to that population with a 100 bacteria per mL in your RODI will make utterly no difference whatsoever.

Keep in mind that your water department is issuing an advisory for any or all of the following reasons:

1) Insufficient chlorination/chloramination detected at various sampling points in the system.

2) Detection of total and fecal coliform bacteria above the drinking water testing limit in municipal water systems. While the limit is "zero" for total and fecal coliforms, this does not mean that all samples must be negative - the limit is 5% of the samples showing the presence of coliforms.

3) An actual system break where air can enter the system.

Keep in mind that an average human ingests quite a lot of organisms everyday that could potentially cause disease. But if you have a normal immune system, it typically requires ingestion of a truly contaminated liquid/solid with thousands to millions of these organisms.

That doesn't mean I'm suggesting to you to not boil water for drinking or brushing your teeth (or drink bottled water, or sterilize the municipal water by other means such as filtration or addition of chlorine). But you shouldn't panic - it is definitely possible your municipal system has a testing issue, not necessarily a water system issue.

If bacteria isn't a concern, I am still concerned about everything they're adding into the water to fix it. Would my unit be able to a) remove all of it or b) do so without damaging my resin and filters?

 

[dkeller_nc]

If bacteria isn't a concern, I am still concerned about everything they're adding into the water to fix it. Would my unit be able to a) remove all of it or b) do so without damaging my resin and filters?

Yes. The only thing they can add (legally) to the water to rectify a microbial issue is a slightly higher level of chlorine/chloramine, which your RODI system will easily handle so long as your carbon blocks are in good shape. Anything they might be adding for corrosion issues would also be easily dealt with by your RODI (that's typically calcium hydroxide, btw).

 

[nereefpat]

Chlorine is hard on RO membranes, so it might be worth replacing the carbon blocks after this is all over. If using chlorinated city water, you should replace carbon filters at least yearly. They are cheap anyway.

 

[Airborne12B]

Yes. The only thing they can add (legally) to the water to rectify a microbial issue is a slightly higher level of chlorine/chloramine, which your RODI system will easily handle so long as your carbon blocks are in good shape. Anything they might be adding for corrosion issues would also be easily dealt with by your RODI (that's typically calcium hydroxide, btw).

Right on! Thank you much!

 

[Tautoga]

Bent is correct. E coli is used as an indicator of human pathogens in the marine environment to ensure the safety of harvested shellfish for human consumption.

My office regularly collects samples from our area bays and cultures E coli from seawater that is 25-30 ppt. So it lives long enough.

In any case it's not worth messing with the risk.

Be careful, stay safe.

 

[disc1]

It's not that the bacteria can or can't live at a certain salinity. It's the rapid change in salinity, especially going down, that will kill them. E. coli will live in tap water. But if you take a culture that's been growing in hyper saline water for some time and just dump it into fresh tap water then a lot of it will die from the osmotic shock. Whereas if you had slowly reduced the salinity they may have survived going even lower.

 

[dkeller_nc]

It's the rapid change in salinity, especially going down, that will kill them.

Yep. We use the osmotic shock technique at work on a frequent basis to kill bacterial cultures before further processing (including E. coli cultures).