How big are the Silver Dollars you are keeping it with? Are there hiding spots in the tank?
The silver dollars are between 3-4 inches. No one is being aggressive except the rainbow shark - and he mostly chances the smaller rainbow shark. They will both be going to a new home once they finish QT. There are two castles - hollow with lots of hiding spots.
Everyone is looking better than when I picked them up 2 weeks ago - gaining weight and getting much more colorful. Once they have past the 5 week mark I will be moving them around to other tanks. The silver dollars will go to my 72 and I will move most of the smaller schooling fish to the 36. That should make it peaceful for the silver dollars and the lonely Tetras will hopefully get along with the other Tetras and Danios.
I am still not sure of what to do with my 'mystery' fish. She seems very calm and comes to meet me when I go to the tank. She does not bother anyone else in the tank - I am just not sure if she would do better in a planted tank with the smaller fish or in the larger tank with the silver dollars and Black ghost knifefish. My BGK is not aggressive at all and has not bothered any of the fish in that tank - not one nipped fin or injury at all. He just minds his own business and goes on his way.
Thank for the advice - I will read up to make sure I understand the care and feeding that she needs to be strong and healthy. She has certainly been more active in the last few days and she is showing more color. I hope that means that she is healing and getting stronger.
Any advice on should there be more than one? Male/female? Do they like to school?
Sorry - but I have very little knowledge about these fish and not knowing which 'type' makes it a little harder to know what are general guidelines for the breed and what is specific to a particular breed.
its likely a female apisto, at least based on the colour.
most male apistos are quite colourful, the females are not.
they are generally peaceful, you could probably put this one in your 10 gallon if you wanted. Or, when you move the SD's out you could get a few apistos from your LFS in the 36.
I know the stores by you often carry Apisto Caucatoides, McMasteri, Borelli and Viejita