pH of Ottawa tap water

[Fletch]

So I'm just setting up a new 35 gallon tank and began cycling with 4 Platies yesterday. I noticed on a City of Ottawa webpage that city tap water runs about pH 8.4 to 8.8.
I haven't had a chance to actually test the pH in the aquarium yet (will do so tonight when I get home) as I have been kind of focused on ammonia, but clearly this pH is pretty high for most FW aquarium fish. Is there some natural process in the aquarium that will automatically lower it ? (I don't know . . . minerals in the gravel, exposure to the air, bacterial action ??) Or do people in Ottawa all have to artificially lower their pH?
I'm guessing I'm worried about nothing, but I'm hoping someone can put my mind at ease.

[mm]

The city of Ottawa adjusts the pH level temporarily using sodium hydroxide in order to minimize corrosion effects in the distribution system. According to the 2013 annual reports the pH level leaving the treatment plants is around 9.3. However, when the water comes out of the tap and the dissolved gases rebalance with the atmosphere the pH will drop to around 7.4 ( in my experience). Both KH and GH are around 2 in ottawa. With a CO2 concentration in equilibrium of approximately 2ppm (my experience and assumption) and a KH level of 2, pH should settle at around 7.4 as stated above. You can do the experience yourself. Let the water stand for a few hours and measure the pH.

Here is the link to the latest water quality reports (brittania and Lemieux purification plants supply most of Ottawa). Always a good idea to know what you are drinking and putting into your tank

http://ottawa.ca/en/residents/water-and-environment/drinking-water/city-owned-wells-and-purification-plants

Concluding, you should expect the pH to setlle at around 7.4 if you do/add nothing.

[exv152]

So I'm just setting up a new 35 gallon tank and began cycling with 4 Platies yesterday. I noticed on a City of Ottawa webpage that city tap water runs about pH 8.4 to 8.8.
I haven't had a chance to actually test the pH in the aquarium yet (will do so tonight when I get home) as I have been kind of focused on ammonia, but clearly this pH is pretty high for most FW aquarium fish. Is there some natural process in the aquarium that will automatically lower it ? (I don't know . . . minerals in the gravel, exposure to the air, bacterial action ??) Or do people in Ottawa all have to artificially lower their pH?
I'm guessing I'm worried about nothing, but I'm hoping someone can put my mind at ease.

The pH that first comes out of your tap will always be higher. It will slower lower over the next 24-48 hours. My tap water in the west end is somewhere between 7-7.2 once it settles. But I wouldn't concern myself too much with pH as fw fish will adapt to just about any parameters that come out of our city tap water. I've seen too many folks make a bigger disaster by trying to change their water parameters, rather than work with what they have. Unless  you're planning SW or African cichlids, I wouldn't recommend altering the pH.

[Fletch]

Thanks everyone!
I checked the pH in my new tank this evening and indeed it looked about 7.6 - 7.8. However, I did a 50% water change yesterday so maybe it will lower further by tomorrow.
Out of the tap I got about 8.4.
Good to know the pH will not be an issue. I want to put some tetras in eventually and i've been reading they like it in the 6s. But I guess cardinal tetras can adapt to the low 7s.
Excellent!

[Fletch]

I hate to be a bother but I have one other question.
(by the way, 2 days after adding a bunch of new water, my pH is now down to 7.4)

If the pH out of the tap is about 8.4, and the pH in the tank is about 7.2, and a person wants to do weekly 50% water changes, is this going to put the fish into pH shock and hurt them? It seems that immediately after a 50% WC the pH would immediately rise from 7.2 to 7.8.
Is this change too low to be of concern, or is there some way around this (ie, do smaller water changes more frequently)?

I also realize that Ottawa tap water is chloraminated and so has about 0.5ppm Ammonia out of the tap as well, however I don't see this as being much of a problem as even after a 50% WC you would only have 0.25ppm, and then it would (presumably) be consumed by the bacteria within hours. Right?

Sorry for the newbie questions, but I am paranoid about killing fish (and the resultant horror this would engender in my kids).

[charlie]

It`s not a bother by any means, this is what this forum is here for 
The PH swing is not of any concern for the most part, unless you have some very delicate fish life that is sensitive to minor shifts.
Regards

[bergenm]

I didn't think most pH test kits could register over 7.4 or 7.6... I was surprised when I started using a Hi-pH kit on my pond that it was sitting at 8.2.

[mm]

As Charlie mentioned, in a cycled tank (with no detectable ammonia) a pH swing from 7.2 to 7.8 is not a problem. Fluctiations of up to 1.0 happen frequently in nature in small bodies of water with low buffering capacity as the concentration of CO2 fluctuates over the day. Basically, what is happening is that CO2 concentration will decrease and then gradually rebalance with the atmosphere. All other important water parameters, including the amount of salts like calcium and magnesium ( responsible for your water hardness -GH), the ammount of carbonates (responsible for your buffering capacity -KH), etc stay approximately constant as long as you are using the same water source.

Having said this, you should note the following. Ammonia dissolved in water exists in two forms.: ammonium ( NH4+ which is not very toxic) and free ammonia (NH3 highly toxic). As the pH increases, the the fraction of free ammonia (toxic) increases. If your tank is still not fully cycled and there is a detectable level of ammonia, an increase in pH would lead to a temporary increase in free ammonia. Make sure that when you make the water change you use a product like Seachem Prime that temporarily neutralizes that ammonia.

With respect to chloramine, if your tank is fully cycled it will process the small amount of ammonia very quickly. Again, using a product like prime is important to avoid an ammonia spike. Note that the recommended dose for chloramine is higher than the standard dose. A product like Seachem Stability might also help in the beginning if you are doing a cycle with fish (a fishless cycle would have been better to avoid potential fish losses).

I hope this helped.

[mm]

I didn't think most pH test kits could register over 7.4 or 7.6... I was surprised when I started using a Hi-pH kit on my pond that it was sitting at 8.2.

I like to use this type of digital ph meters:
http://www.amazon.ca/Brainytrade-Digital-Ph-Meter-Tester/dp/B0054IQCB4/ref=sr_1_1?ie=UTF8&qid=1423080989&sr=8-1&keywords=digital+ph+meter

After being properly calibrated, I find them to be quite reliable and precise for a wider range of pH values and much cheaper than the liquid tests.

[Fletch]

Very informative! I'm learning a lot.
If I'm filling water with a python (ie, right out of the tap) can I still add a dechloraminator (or Seachem Prime, or whatever product is used) to the tank while adding, or is this going to result in swings in NH3 due to the fluctuating pH (in an uncycled tank)?
However, this may be moot in my case as my NH3 levels started dropping today (not that they were ever high to begin with).
Those digital pH meters look cool.

[exv152]

Very informative! I'm learning a lot.
If I'm filling water with a python (ie, right out of the tap) can I still add a dechloraminator (or Seachem Prime, or whatever product is used) to the tank while adding, or is this going to result in swings in NH3 due to the fluctuating pH (in an uncycled tank)?
However, this may be moot in my case as my NH3 levels started dropping today (not that they were ever high to begin with).
Those digital pH meters look cool.

You can add any type of dechlorinator before, during or after. Don't worry about ph, nh3 or any other type of swing, just enjoy your aquarium.

[mm]

Yes, you should add a dechloraminator. Learning new things adds to the joy of keeping an aquarium.