Adjusting PH

[dvdlard]

I've mentioned here before that my tap water has an extremely high PH (over 9) and has proven to be lethal to my fish if untreated. This means that every time I do a partial change I have to adjust the PH to seven. Although this has worked fine for many months it worries me that I keep reading that you shouldn't do it.

Because our tap water isn't particularly nice to drink we always run it through a britta water filter jug and I was wondering if the filtered water would be better for partial water changes.

With this in mind I ran a full set of tests on the filtered water and came up with the following results:

PH: 6.0
GH: 2
KH: 2-3
Nitrite: <0.3
Nitrate: 0-10
Ammania: 0

So my question is what do you think would be the lesser of two evils. Adjusting the PH or using the filtered water?

 

[dvdlard]

Bump.

 

[Cian McLiam]

Using the filtered water is definitely preferable to adjusting the water in the tank BUT you say you will be using the water jug filter? If thats the case then I hope you have plenty of patience! It could take a while to filter that much water through, but if you come up with a contraption to do it for you, let me know!!
The problem is, what if in a few months you get tired of filtering and start putting in normal untreated water again, which is what would happen if I was doing it. Then the change will come as a shock to fish used to soft acidic water...

BTW Aquarium Pharmaceuticals have a tap water filter and from what I can make out, its just a bigger version of the type of filter used in your jug. Heres the LINK

Ken