What kind of mechanical parts, I have a 125 and a 180 up and running with external filters and wet/dry, they both have 2 fish in them, discus and clown loaches respectively, I have more stuff for them as well, stand lights, more filtration and overflows..... 55 gallon set up no fish but with water in it, Just let me know what exactly you are looking for and type of fish you want to put in and I will recommend the type of lights and filtration