What they said! And goldfish are pretty tolerate of more extreme pH levels. But 7 or 8 is vague and a 10x difference between them. If it fluctuates that is problem. Like they said, stability it the most important thing. It can be good to know if you have a high pH though, like 8.0+ (like me) cause some things react differently in higher pH. Most notably is that certain things are more toxic at higher pHs, like ammonia-nitrogen. Hence why keeping up on water changes is crucial in alkaline water.
Not versed in city water and there nasty additives but a quick google search tells me sodium hypochlorite is basically bleach and I know we can use Prime water conditioner to neutralize bleach. But PLEASE don't take my word on this, wait for someone to confirm.
Prime will handle that...read the Wiki page on it and what it breaks down to. Besides disinfecting water systems, it also can eliminate cyanides common in agricultural ground water from fertilizers and weed killers.