Brown patchy deposits inside canister hoses

[bernie]

What are those brown slimy deposits ? Do they need to be removed occasionally and are they signs of unhealthy tank water?

[vinz]

They are normal. You probably discovered by now that they will be ejected if you turn off the filter and turn it on again. They do affect the flow rate a little, so good to remove them once in a while, especially if you clean the filter. For me, I just detach the hoses, bring them to the toilet, attach them to the tap (or just hold them to the tap tightly with my hand) and run tap water through them. Repeat in the opposite direction.