Ph Stable @ 8.0, Kh: 1 Degree!?!

[Jeremy180]

I was  told by somebody here a few days ago that 6 degrees Kh was lower than expected for my ph, so I re tested it a bit more carefully today, and came to find out that I had misread the directions the first time I tested, and that instead of changing from blue to orange, I was supposed to add drops until It changed from Orange to blue, which is happening with one drop, which is  1 degree.
I double-checked my water suppliers' 2015 water quality report 
http/www.mawss.com/waterqualityreport.pdf
And apparently these were the highest detected levels of buffering minerals and highest ph detected in 2014:
Calcium 18.7ppm
Magnesium: 1ppm
Highest PH: 8.3
 
The only thing I can figure is that my water supplier has added something to artificially raise the Ph,
It's too late to contact them today to see what they added, but apparently it's somehing very stable.
 
So, how should I treat this water? should I:
Stock according to mineral content (neon tetras)?
Stock according to Ph (Guppies) without making changes?
Stock according to both PH (guppies) and mineral content (neon tetra)?
Stock according to PH (Guppies) after adding the minerals that would be expected with Ph this high?
 
EDIT: Are there any fish that naturally live in water like this?

 

[Byron]

I have much the same situation where I live.  I read through the linked report, and it does say that they have implemented a corrosion control program (this targets the pH), plus in the diagram at the bottom of the first page there are two stages labelled "pH adjustment," but I could not find anything as to what exactly they are adding/doing.  Here in Vancouver they add primarily soda ash (sodium carbonate) and at one of the three stations, also lime (calcium hydroxide).  The soda ash has been added since 2001 and I have noticed no issues; the lime is more recent but nothing seems to have changed.  These substances are used to raise the pH, but the GH and KH remains unaffected; raising the pH is done to alleviate corrosion in pipes and appliances from acidic water.  I have found that the individual aquaria establish their own pH naturally, and in all seven tanks it ranges from 5 to mid-6.  The GH and KH in the source water are around 7 ppm, which is even less that the levels of your water shown in that report of 15-39 ppm GH and 5-10 ppm KH (alkalinity).
 
Without knowing exactly what they are doing/adding to raise the pH, I cannot say the pH will naturally lower over time in the aquaria due to the normal organic processes or not, but I would suspect it might.  The buffering capability of your Alkalinity (KH) is minimal, so this will allow the water to gradually acidify.  GH is actually the more important of the two (GH and pH), as fish evolved to extract minerals from the water will need these, whereas fish evolved to live in very soft water will have issues with minerals in the water.  The pH is still a factor, but less important than the GH, and provided the pH is not jumping around the fish are better able to adapt.
 
There are a few natural areas where the pH is high (meaning basic, above 7) with a very low mineral content (soft water), but I wouldn't aim to only stock fish from these sources.  I would recommend you consider soft water species.  Most will likely have no problems.  There will be some wild-caught species that are more sensitive to pH issues, but the majority of soft-water species available in the hobby should not have issues; I'm thinking of South American and SE Asian species here.  Livebearers will not do well in your water as there is no where near sufficient hard minerals for their physiology, though having said that, the guppy is something of an oddity as it has been so affected by generations of inbreeding that it seems impervious to almost anything.  
 
If you have had an aquarium running for several months, it would be interesting to know where the pH normally sits.  Always test immediately prior to any water change.  Testing an hour or two after will tell you the difference, if any.  In my tanks, the pH rises by 0.2 at most, but within a couple hours is back to the pre-water change pH.  This may depend upon what is being added.
 
Byron.

 

[StevenF]

 
I double-checked my water suppliers' 2015 water quality report 
http/www.mawss.com...alityreport.pdf
And apparently these were the highest detected levels of buffering minerals and highest ph detected in 2014:
Calcium 18.7ppm
Magnesium: 1ppm
Highest PH: 8.3
 
The only thing I can figure is that my water supplier has added something to artificially raise the Ph,
It's too late to contact them today to see what they added, but apparently it's somehing very stable.

 
Did you notice the section of organic chemicals?  That list is mostly man made chemical or petroleum byproducts.   I have never seen a water quality report with so many man made chemicals listed.    I couldn't even guess as to what these items are doing to your water.  The reset of the report looks fairly normal.  
 
Note any metal listed in the report can increase PH.  this includes calcium, magnesium, and sodium which are listed in the report.  Also many of the inorganic chemicals detected  are metals.  IN comparison dissolved gases or non metals (nitrate, phosphorous, and sulfer) tend to reduce ph.
 
You might want to consider using an activated carbon filter to remove the organic contaminants   don't know if that would affect the  PH.  As to cleaning up the rest of the water the only thing I know of to do it is an RO filter.