Hi, I am planning on having some Cardinal Tetras in my tank. It has just finished cycling and I will add them in a month or two, but my PH is 7.5 and unless I alter it using chemicals which I don't want to do, it will more or less stay the same. Can I put the tetra in with the PH at this level?
Yep I agree with Brianna. I'm running Red eyed tetras in the same Ph as you. They are happy and healthy. It's a really hard thing to control the Ph and you are right to not what to cross that bridge. It's better to just keep the Ph constant and let the fish get used to it then to have it bouncing all over the place.
I shall leave the tank for a few more months before I add the tetras, just to make sure its mature enough. I am going to have a betta but I am not sure which tetra to put with it it - the neon or the cardinal?
Your fish should be ok with the pH as long as it's steady.. if you're using the same tap water as the store, they're probably used to it when you get them. Putting the Betta in last is definitely the best way to go to give the community tank the best chance of succeeding. As far as Tetras go, I'd not go with flashy ones (like neons) that might get the Betta thinking "betta rival - attack". I believe that mostly Bettas will tend to not be kind to fish that have big fins or are really bright/colorful because it gets their territorial instinct going.