Miss Wiggle
Practically perfect in every way
the key to pH is stability.
some fish are sensitive to it and will only survive in a certain pH range, some are less sensitive but will only spawn in certain conditions. But the vast majority of community fish can easily adapt to a pH a few degrees outside of they're prefered range.
Trying to change your pH on the other hand can be very dangerous and tricky. It's nigh on impossible to get a gradual change of it going up or down a point or two and staying there. It tends to swing wildly, like with adding rainwater you may find your pH now drops quite sharply, and when you do water changes it'll swing back up again. This is very bad for the fish and should be avoided if possible. If you find your pH is massivly different to that of the fish you want to keep then you should adjust it nad make sure it is stable before adding fish. This is one of the benefits of fishless cycling, it gives you a few weeks to research, decide on stocking and make any nescessary adjustments to your tank to make it suitable for the intended inhabitants.
Basically if it aint broke, don't fix it.
