I just cleaned the top pad from my Eheim basket on the 2213. It's crazy how much the flow has increased. It's not like it was bad before but I just had to replant a bunch of plants since the flow uprooted a ton of cuttings.
The filter was brand new about 3 months ago. So is it safe to say that you need to clean it about every 3 months?
The amount of time that passes before you must clean your canister filter depends on the size of your aquarium and its bio load.
The filter being used on a well or overstocked aquarium is going to need to be cleaned more often than a filter that is being used on an under stocked aquarium.
Moreover, an oversized filter will allow for less frequent cleanings.
For example, I use a Fluval 305 on a Mr. Aqua 17 gallon aquarium. This filter is rated for up to a 70 gallon aquarium. However, the filter could probably be comfortably used on a 55 - 60 gallon aquarium that is lightly stocked before it becomes undersized; since most filter manufacturers are extremely optimistic with their ratings.
My Mr. Aqua 17 is home to about three dozen female guppies whose bio load is relatively light. So the filter is complete overkill and as such, only needs to be cleaned once a year.
Even then, when I open the filter the media is not nearly as dirty as this filter would be if it was being used to filter the same tank but with larger fish.
Overall, I have found that using an oversized filter makes good sense when you want to reduce the amount of maintenance that you have to do on an aquarium, simply because you have to clean the filter less often.
And this becomes especially true if you are maintaining several aquaria; especially if they are planted.
On an aside, for those who have been considering the purchase of a UV sterilizer, I have found that Cobalt Aquatic's DUO 500 and 1000 series internal filters are quite useful.
There's not much in the way of mechanical filtration with these filters, so I decided to just use them as power head/UV clarifiers. They work quite well this way, and you don't have to deal with cleaning them every two weeks or so when the filter media becomes saturated with detritus.
I use the term UV clarifiers because that is basically what inexpensive UV sterilizers are, since their bulbs are cheap and while very useful for polishing the water in your aquarium and killing off algae spores, not as useful as better quality bulbs for killing off larger parasites and protozoa.
A real UV sterilizer has a better quality bulb and ballast and costs a lot more. However, they tend to be overkill in fresh water aquariums, yet, are well worth the additional money when you have a large investment in salt water fish and corals. Or even a fresh water set up with a tank full of pricey Discus.
For polishing water though, an inexpensive UV clarifier will do an excellent job of keeping your water column looking crystal clear.