High pH in Tap Water, Is It Good Or Bad? Options

[chugin]

Dear All,

I am a relative newbie and have just started keeping goldfishes again after a break of a few years. Got some small ranchus last week and housing them in a 4 ft. tub. Running 2 cannisters- 1 x Eheim 2215 & 1 x Atman 3336.

I have tried searching the forum but I don't seem to find what I need. My question is:

My tap water's pH is 8.7. Is this a bit on the high side for ranchus? Do I need to bring down the pH and buffer?
What would be the best method in this particular case. Reading from previous postings here, I gather that the saturation point of BS is 8.4. So would buffering with BS in this instance be a waste of time? I am very confused!! Really need some advice cos I don't want to end up with dead fishes. Right now, they seem to do doing fine.

If the answers to my queries have been dealt with before, I offer my most sincere apologies but I hope that someone would be kind enough to point me to the relevant thread.

Thank you.