I've I'm reading it write from that link, it's good to "control-crowd" your tank but "over-filter." Here was their 30 g suggestion:
http://www.cichlidrecipe.com/cichlidrecipe/crp22.htm
30 Gallon Aquariums
1 trio Labidochromis
1 trio Cynotilapia or Haplochromis
1 trio Copadichromis or Aulonocara
6 small/medium schooling fish (Danios, Rasboras, Rainbowfish, ect...)
1 or 2 Dwarf Plecostomus
If by trio they mean 3 of each, according to this, that would make 16 or 17 fish!!! But, from what I understand a 55 g would be easier to maintain anyway...just looking for more space in my apt
http://www.cichlidrecipe.com/cichlidrecipe/crp8.htm