Hello, so I've been planning to make a canister filter myself for a long time now, but never had the opportunity until now lol. So, basically, I was just browsing through the internet trying to look for clip-on containers larger than like 4 liters, but they're either not available in my country or just simply too expensive. I was wondering if I could use a container that has a screwed-on or just a regular container with a normal lid? They are my only options if I were to go bigger than 4 liters but I'm concerned about the lid not being able to handle the valves I plan to put on it and the incoming flow.
Also, I'm planning to put the pump at the bottom of the canister (because its too bulky and heavy to attach below the lid) and attach an output tube to the pump, then attach the lid to the tube using some sort of adapter. The Fluval FX4 uses this design, and I noticed that their lids have this white thing which seemed to connect to the output tube. Could anyone identify what that is? Much appreciated.