Do you mean wont get a long? If you get two pairs of different species, maybe even the same speicies, in this size tank you will definitely run into problems.As for the acrylic, that was just my guesses, I am waiting for some responses. You say the pleco is not needed, I agree. However, he will knock over plants when they are young if he is startled, the rock scape tank will be a good option. Yes, ideas for cichlid lists are appreciated. Will 4 julies ( the two types listed above ) crash and burn too?