I want to setup a 25cm cube nano.Mainly for some corals and maybe a shrimp. At the moment the tank im going to use has a betta in it.So i already have the heater and filter. the filter is just a HOB filter- Elite Hush 10-its 310lph. Would this be alright? What else do i need? And do i use seawater or mix a salt with tap water?