Six males guppies need a minimum 20 gallon tank, with a heater to maintain a consistent 75F - 78F temperature. The male betta (siamese fighting fish), will present to and nip the fins of other fish having long fins. For this reason, you need to to be very cautious about the type of guppies you put in this tank. Angel fish should not be mixed with male bettas. Neons are schooling fish requiring a shoal of at least 6 fish. If your pleco is the common variety, it can reach a length of nearly 2 feet. It would be irresponsible for me to fail mentioning that a pleco will need a 55 gallon at full adult size. Fortunately, you have a shop that will let you trade the fish when it outgrows your tank. You knife fish will also need a large tank as it will exceed 18 inches in length.
One concern I have in your grouping is that the knife fish and pleco need a neutral to acidic pH, and your guppies prefer a slightly alkaline pH. The neons will tolerate just about any pH. Anything less than a 20 gallon tank is entirely inappropriate for the fish you have. You will need to "trade in" the pleco and knife fish unless you have a 75 gallon tank or larger. Angel fish should not be mixed with male bettas, nor should guppies or any other fish with long fins. |