Bala Shark Seems ill

Hello, I recently have been having some problem with my tank. Everything was fine until I bought some Neon Tetras (5 from Petco 4 from Wal-Mart). I bought the neons about 34 days ago and since then all but 4 have died. I have removed then as soon as I see they are dead. Today I pulled out all the large rocks and replaced them with store bought rocks. I did this because I was told that regular stones/rocks can affect the ph levels. I also moved fake plants to accomidate the tank aliitle better. Now one of my balas is swimming really weird. First it just floats but it's head either floats up or down and the body is striaght up and down. After a bit it starts to kinda flip, it's not doing it it's just floating in that direction. It also floats twords the top. Now if another fish comes around it and scares it it wil jump back upright and swim to the other side of the tank and then start the process all over. It's mouth and gills are going crazy though like it is trying to get air. There is a whitish spot just infront of it's top fin on the side of it's body. I don't get what is going on. I had them in a 10 g tank (I know this was to small now) and it was fine. Since I added the tetras weird things have been happening. My other fish seem fine but like I said I have had 5 tetras die in the last 4 days. I also am noticing that some of the other fish are now nipping at the bala. The balas I have are only 2 inches at the moment and this at this moment is starting to float upside down now. PLEASE HELP.

Nevermind, my bala died. It is weird it was fine and just like that something was wrong. It died within a half hour of me noticing something was wrong. Not sure what happened but it was fine 2 hours before hand. I did noticed that were there was a white mark in the water turn out to be a spot were it was bleeding for some reason. It wasn't bleeding out but I could see the blood unders the scales inside. If anyone has any ideas please let me know thanks. :sad: :sad: :sad: :sad: :sad:

Hello, I read about the rocks on the forums here. I wasn't sure what to use to test then so I just thought I would be safe. I know the rocks were just rocks that were picked up on the beach or next to the road. I prefer the decor I have now in my tank and I think the fish will be happier as they have more places to hide out. As for my ph it is in the 7.8-8.4 range and I can not get it to go down no matter what. I do normal cleaning but it just doesn't do the trick. I have even tried to use the good ol chemicals that lower ph but they did nothing so I thought I would try the rocks.