Fifty five gallon tank

[Kulay Wolf]

I got a fifty five gallon freshwater tank with guppies. The guppies are okay but I am thinking of giving them all to my brother and converting the tank to salt water. Before I ask him if he wants more guppies I was wondering what I need to in order to do the conversion. Can I keep a royal blue tang in a fifty five or is my tank too small? If it is too small what fish can I keep in there? There is some gravel in the tank but not sure if I have to switch to live sand or something?

I am trying to decide what to do?

 

[KJ]

https://www.reef2reef.com/threads/the-supreme-guide-to-setting-up-a-saltwater-reef-aquarium.138750/

 

[Kulay Wolf]

https://www.reef2reef.com/threads/the-supreme-guide-to-setting-up-a-saltwater-reef-aquarium.138750/

Thanks