It becomes important, yes. Bio-film will build up in the tubing, and in the long run, can result in floating solids as the bio-film breaks loose. An easy way to clean them-other than pulling them off completely and running a pipe cleaner through--is to drain them, remove the them from the canister, then start a siphon into a bucket from the main tank, and let the water wash through. This will remove some of the loose film, but you'll still need to plan regular removal and cleaning, IME. I usually can go about 6 months before I need to clean them. Keeping the tubing covered will also help prevent algae growth, which can require more frequent cleaning and result in lower flows.