the tank is four sided and some what triangular and the top is attached to tank
you can take a small peice of pvc pipe or a hose that will fit and put it on there. and if it needs a cover you can buy a small peice of mesh like what is on a screen door. that should work fine untill you can find the right peice.
You can go to your local fish store and ask them to order you a new uplift tube for your UGF.
Sounds like you are describing a lift tube and that can be purchased at your local fish/pet store and cut to size to fit.
A pet store should have plastic tubing that will suffice to replace yours. Or you can tell them the size and shape of your tank, and they'll show you the underground filters you can buy to replace yours entirely.
Well, you could get some PVC tubing and cut it to size, but that would probably cost as much as just getting a new filter. You could get a new UG filter (undergravel) but frankly, UG filters are not very effective. In theory, they suck all the gunk, poop, uneaten food into the gravel where it can biodegrade. It's a good idea, but in reality, the gunk just rots. It's like if you threw food, and pooped in your backyard. If you only did that a teeny bit, it might biodegrade, but if you did that alot, it would just pile up and rot. That's basically what happens. In a 5 gallon tank, waste adds up very quickly, even with just one fish. I suggest you get a hang off the back (waterfall) filter. They are much more effective. You'll still need replace 20% of the water every week, but it'll keep your tank crystal clear.
