Some breeders use 2.5 gallon tanks, others use as big as 20 gallon 
     tanks, while others use odd sized plastic tubs.  We have found that
     20 gallon long tanks work best for us.  With time you will figure 
     out which works best for you, but give yourself some room and at least
     for those first few times a 10 gallon should work fine.  Around here
     new 10 gallons cost the same as new 2.5 gallons so why use the 
     smaller one.