i dont think 7-8 females and 4 cories will do. sounds like overstocking the 20g. from what i understand 20g is close enough for the sorority alone. your cories and HM male sound more feasible as to stockong options. i beleive cories need atleast 6 to be comfy as far as security in numbers. not sure how well 4 cories will fare as i dont have experience with cories.
your 5g options sound fine. its personal choice as to single betta minimum tank size but you can put 2 betta in the 5g providing its a divided tank.
Kigurumi (F) yellow PK 7/4/13, Kurama VT 9/8/13, Zeydalus Salamander EE PK 21/3/14, Ryuk turquoise dragon DeT 8/5/14----Crested Gecko (8ths old) Sven Cal 27/12/11,
RIP: Osiris copper DT, Nel blue VT, Nelliel turquoise grizzle DT, Zaku red cambo, Blitzkreig Pineapple CT, Halloween orange chocolate DeT, Grimmjow, turquoise green CT
Last edited by nel3; 10-10-2012 at 08:33 PM.