WATER QUALITY WARNING!!!

[Jessi Tench]

Hey OVAS members!
I'm putting out a warning because I almost just lost all my goldfish, and Im fairly certain it was Ottawa's tap water!
I did my regular maitenence yesterday, and noticed this morning that the fish had taken a sharp downturn, classic symptoms of chlorine poisoning. I added more conditioner but it made no difference and I didn't want to poison them furtur, so I rushed to my local shop to get the water tested. My parameters came up pristine, and when I explained what was happening the clerk told me that sometimes the city heavily overchlorinates the water in the event of overflows! (Like 8x the usual amount, after a thaw like the one we had recently)
This info came from someone who actually workedß for the city, and apperently it was in the news just a little while ago...
I rushed to the store for enough bottled to change the water and they've perked up, but I'm unsure if the damage has been done.
Basically, if you were planning on doing water changes this weekend, DO NOT!!!
Clearly there's something wrong, I've tried contacting the city about this, last year when the same thing took out half my collection, but 6 conversations later and no one could tell me...

SO LEAVE IT TILL NEXT WEEK JUST IN CASE! I know a few of us keep rare and expensive stuff.

[matttimms49]

Thanks for the heads up, has anyone else had any problems regarding this?

[ksj]

How long should we wait? I need to add more water to my tank.

[sniggir]

If you use Prime as apposed to some of the cheaper water conditioners, it will remove both the chlorine and chloramine I will do a double dose as it says when dealing with higher doses of Chloamine and should be fine, if you cant wait that is, I stay away from the other water conditioners as they don't deal with Chloramine very well.

[charlie]

Thanks for the heads up, has anyone else had any problems regarding this?

Will let you know when I get home tonight,I did large water changes (50% +) this  morning on all my tanks including shrimp tanks.

[charlie]

Everyone  is going swimmingly good no issues here

[Black_Rose]

No issues here (Barrhaven).

Did 50% water changes on 7 tanks today and no issues.
Used Prime for 6 of them, and Betta Basics for the betta tank.

[nerdRVT]

One thing that people don't think about with water changes this time of year is the nitrogen supersaturation issue in city tap water. As the temps get colder, city water gets colder too, and the pressurized water becomes supersaturated with atmospheric air, which is largely nitrogen. At high enough levels, this *will* kill your fish. At low levels, it will cause chronic injury and may put your fish at risk of illness due to microscopic wounds.

We monitor total dissolved gases at work and also chloramine, all the time. We did not see a spike in chloramines but we are constantly observing city water getting colder (this morning it was 1.8C coming into my facility), and the total dissolved gases in the pipes coming straight in from the city are at high enough levels to kill most fish very quickly. 115-125%, Fish get the bends and die at these levels. We tend to call it 'gas bubble disease'.

[matttimms49]

That's really interesting, thanks for the information. Is there anything we should do during water changes for these high levels of nitrogen in the tap water?

[nerdRVT]

The best thing you can do is throw an airstone in the water in a container for an hour or so. The scary thing is that the nitrogen in solution is invisible, but this time of year, when the city water is approaching freezing, you have to assume the water is approaching dangerous levels of dissolved nitrogen.

You know how in the winter, the water comes out of the tap looking 'cloudy'? It is actually air bubbles coming out of solution. This is when we're approaching dangerous levels of dissolved gases in the water.

We use a lot of directly dechloraminated city water (sometimes, 30L/min or more for our animals), and to make it safe, we have to run it through degassing columns before the water gets mixed with the existing water in the system. These are 3-7 foot tall, 6-12 in diameter PVC columns full of plastic media, which causes turbulence in the water as it trickles down, allowing excess gas to escape. For cold water species, we'll use more than one column in series before the water gets to the animals. In the bad old days, before these columns were installed, the fish would die of the bends as soon as the city water get close to about 5C in the city water mains.

[nerdRVT]

I should add as well, I'd also heard the urban legends about the city 'shocking' with chloramine. I looked into it as part of our evaluation of our dechloramination system, and the city said they don't actually do that.

We use activated carbon as our front line dechloramination system, with sodium thiosulphate as a backup. In 20ish years of running said system, never had a chlorine breakthrough, but tons of issue with gas supersaturation.

[charlie]

I have been doing massive water changes, sometimes as much as 80% for the longest while in the winter spring summer and fall  I have never had any related issues.
One thing I do is have the water entering the tank via a python hit the palm of my hand,creating a splashing effect before entering the tank.
This is something told to me by a well known hobbyist.

[nerdRVT]

When the water is warm, or mixed warm and cold, the nitrogen saturation risk goes down quite a lot. Water that's been sitting in a hot water heater has been off-gassing, plus atmospheric gases overall are less soluble in warm water. The colder the water, the higher the risk.

That being said, we have a 28C reservoir for one of our bigger tropical fish rooms, and I have had to really work to get the total dissolved gas levels down to a level where I'm not concerned about injuring the fish. Even 105-108% is approaching injury or serious effects, depending on species and life stage.