When I bought my 90 gallon it came with a 12-14 inch Oscar. The guy had never taken the fish out of the tank so the only net he had to catch the fish was the little one he got when he got the tank. The fish's head barely fit it, and the guy grabbed it by the tail to get it into the bucket I had bought. Since then I always bring everything I may need when I buy a tank, including a water changer with sink adapters.
125 - BGK, chanchito cichlid, pictus cats, silver dollars, palmas bichir
125 - cichlids (severums, bolivian rams, chocolate), rainbows ( turquoise, red), loaches (angelicus, zebra, kuhli and horseface), plecos (BN, RL and clown), denison barbs, tiretrack eel, pearl gouramis, betta
90 - Congo tetras, african knife, upside down cats, spotted ctenopoma, kribensis, delhezzi bichir
2.5 - betta