A short comparison between Monte Carlo and Cuba. The two may look similar, but are miles apart in the care and conditions required to grow them well over time.
 
But then CUBA tend to have a bit smaller leaves and tighter growth
 
Monte Carlo
 HC 'Cuba'
CO2?
Good to have
Must have
Substrate?              
Not necessary            
Prefers substrate
Overcrowding?
Resilient
Not resilient
Care level
Low
High