I agree with Zagz as well. Your Goldfish prefers 65-70 degrees, while the tropicals much prefer the mid 70s. Strongly suggest re-housing the Goldfish, at least.
Although they mostly are classified as peaceful, the CAE
is semi-aggressive, and probably will grow to as much as 10 inches. Being in a 10 gal
only will increase the stress and feed aggression. Sorry to rain on your parade, but bettter to know, for all's sake.
BTW, welcome to the forum. We all love horses and cats, too. Enjoy your stay here and visit often, love to hear from you.
Regards to the "Big Apple."