What is going on

[JoeDaniels]

Ok so recently I bought some cardinal tetra and the other day one just went missing but I thought not to worry it will turn up but today another 2 have died overnight and the other one still hasn't turned up :/ why could this be :/ they don't have any signs of illness either :/

 

[roydooms]

Hi Joe. What's your tank's parameters? We need this so that we can better help you. Did you cycle your tank?

 

[JoeDaniels]

My tank was fully cycled 2 years ago by the previous owners and I moved it all in the appropriate way, losing as little bacteria as possible. It's roughly 50 gal and my ammo is 0 nitrite 0 and nitrate about 40 now my cherry barb is swimming weirdly :/ he is swimming facing downwards constantly :/