The Neon Tetras and Guppies will be okay, however, Clown Loaches get to be around 8" long and must be in a group of at least 5 in a 125 gallon aquarium (24×72") or larger. I would highly suggest you give the Clown Loach to someone with a proper tank and possibly get a few Corydoras or Shrimp, which will help keep your tank clean. Also, Neon Tetras are best suited in groups of at least 10 or more, which will require a 10 gallon alone. I would recommend you have 6-8 Neon Tetras, the Guppies, and add a few Shrimp or Corydoras. I hope this helps! Good luck!