Is your aquarium overstocked it has 1 betta 5 neon tetras and a stone sucker?

Yes, the aquarium is overstocked. The rule of thumb for stocking an aquarium is one inch of fish per gallon of water. Bettas need a minimum of 2.5 gallons of water, neon tetras need a minimum of 1 gallon of water per fish, and stone suckers need a minimum of 3 gallons of water. Therefore, the minimum tank size for this setup would be 10.5 gallons.