Aquarium Plumbing Parts

[Eb0la11]

What parts do you find essential in your system in terms of plumbing?

I have configured systems in the past with mostly pvc pipe and don't like the rigidity of it and would like to hear how people are softening some of their plumbing, especially anywhere a 90 degree would be required.

Also, if you dont mind on commenting where in Calgary you found these parts? The best places I found parts was Rona and Western Pump. Home Depot has some but not a lot often times.