I'm in the process of buying all the pieces now but I have put together regulators for air compressors and air tool setups so I'm sure it is similar. The regulator is going to have a fitting off the side of it that is a certain thread size (1/4", 3/8" npt etc). You can buy brass fittings from the hardware store that are male or female or a combination, bent straight etc. Also you can buy fittings that will let you say connect a 1/4" npt fitting into a 3/8" npt fitting if your components do not match up properly. So anyway you get your pieces figure out how you will piece them together (regulator -> solenoid -> needle valve --> bubble counter) using wrenches and teflon tape except for in front of the selenoid use pipe dope. You can use any connectors you want as long as the pieces fit together without leaks. Off the bubble counter you can just put on a hose barb to connect your aquarium tubing. Hope this makes sense and anyone else correct me if I missed something but if you can turn a wrench you can put a regulator together quite easily.