Question about planted aquarium and fishless cycling

While Panda corydoras might be one of the most fragile corydoras catfish around, most corydoras species will do fine in your water. My tap water has a PH of 8.0, and my Peppered Corydoras catfish have no problem with it while most sources say they prefer 7.0 or lower PH. It just proves a lot of fish species can adapt to different water PH easily as long as it is not too extreme. Your PH of 8.2 isn't that far from my 8.0.

Although there is one thing about the Peppered Corydoras, they aren't that pretty. So look around for better looking corydoras if you wish to have something as eye candy.

Check this page out for more species of cory catfish.
http://www.liveaquaria.com/product/aquar...c=830+1161
Keep in mind you need minimal 5~6 for a school. Or they will be shy and hide most of the time.

As for the potential nipping problem, if you see damaged fin on guppies, then it is most likely the work of Zebra Danios. They might not be nippy until they are nippy. Once they get started on nipping around, especially after there are already some damaged fins, they will more likely to nip on the damaged fin continuously. So I'd keep eyes on them, and keep watching for damaged fins on guppies.