If you are going to start adding tubing, you might as well go with a larger diameter hosing and redo the whole setup. (Trust me making hosing that is 3/4 ID is much faster.)
But if you still want to stay with your python setup, the tubing they use is 1/2 inch ID with 5/8 OD. You can just cut the tubing and use barb coupling with any 1/2 ID tubing, or if you want to use their parts you will also need the right OD.