I don't know about everybody else, but I have had no luck with tetras. I tried the cardinals, because they are supposedly a little hardier than neons. Well, I bought 5, and within 48 hours there was only one left, then he got ick and held on for as long as he could, I thought he'd make it. But, he didn't. All my water peramiters were great, exept that I had a high ph like you. Could that have been it? I don't know, but I still want a school of fish so I'm going to try white clouds, They look just like tetras exept for the color.