What can i use for a replacement of the tube part in a fish tank filter?

i bought a used fish tank with a built in filter.i can see how the filter works but the part that sucks in the water is missing. i can see where it is soposed to fit but its just not there and its not in the box. what can i use for a replacement?What can i use for a replacement of the tube part in a fish tank filter?The tank is probably set up for an under gravel filter, but if you have a carbon filter (anything with a pad or cartridge) then you don't need to worry about it. If it just has a powerhead, then I'm sure you can find the tubing at a fish store.What can i use for a replacement of the tube part in a fish tank filter?measure it and see if you can match it with PVC, which you can get cut at a local hardware store.