I don't see much difference between the two tanks, but the bigger the better. Personally, I wouldn't expect to keep a fully grown pair in less than a 125. They'll still do their business in a 75 (or a 55 for that matter), but I feel better about the larger tank for a lot of reasons, one of which is the ability to keep some other fish as targets/dithers.
On another note, I have to differ with your comment that we don't see natural behavior in "any" aquarium. Certainly the tanks have to be much large than most people would be able to provide, but medium sized cichlids kept in several hundred gallons of water exhibit much different behavior that those kept in much smaller tanks. In fact, my goal in fishkeeping it to attempt to stimulate as much "natural behavior" as possible (the definition of natural behavior is, granted, up for interpretation).
As a start toward a more natural setting, a tank needs to be larger than the average size of the wild breeding territory of a given species. For Archocentrus or Cryptoheros that may be just a couple of square feet, but for your Amphilophus it may require double (or triple) that. So, unless you are heading toward a much larger tank, you are accepting a certain level of compromise with your labs. That doesn't mean you can't keep them plenty healthy though.
Any pics of your labs? Would love to see them!
On another note, I have to differ with your comment that we don't see natural behavior in "any" aquarium. Certainly the tanks have to be much large than most people would be able to provide, but medium sized cichlids kept in several hundred gallons of water exhibit much different behavior that those kept in much smaller tanks. In fact, my goal in fishkeeping it to attempt to stimulate as much "natural behavior" as possible (the definition of natural behavior is, granted, up for interpretation).
As a start toward a more natural setting, a tank needs to be larger than the average size of the wild breeding territory of a given species. For Archocentrus or Cryptoheros that may be just a couple of square feet, but for your Amphilophus it may require double (or triple) that. So, unless you are heading toward a much larger tank, you are accepting a certain level of compromise with your labs. That doesn't mean you can't keep them plenty healthy though.
Any pics of your labs? Would love to see them!
jk.
someone! I dont know him but the guy takes care of his fish.talking without investigating only makes us look foolish.Also ithink he was just looking for opinions becouse he does care for the fish.ya know simple input.