Biotine loaches form a complex social structure with a regularly challenged pecking order, in small numbers there tend to be more aggressive with each other and others in their tank. I was recently able to finally up my Dwarf Chain Loach group from six to thirteen, the young newcomers have made the older ones far more active and their behavior has changed massively for the better.
Red Tail Botia are not small fish (~25cm SL) and they are a more fiesty than Dwarf Chains or Clowns for example, so a good sized group of 10+ is going to need carefully chosen tankmates and a tank with a footprint of at least 150x60cm.
Your Dojo should be in a social group too, they are very social creatures with much less pecking order aggression. Again, 10+ is desirable and their adult size of ~20cm needs a large tank, my eight were very sedate by day but by night they were doing lap after lap midwater in my 5x2x2. They are not tropical, they are temperate, an unheated tank in most cases will suit them well that varies somewhere between ~10-20C through the year.
