From :
http://www.plantedtank.net/forums/p...roper-cleaning-eheim-canister.html#post144227
Call this the First Half Maintenance.( 3 months from Initial start-up)
1. Unplug the filter and shut off all of the valves.
2. Now, disconnect the valves and take the filter to the kitchen.
3. Grab a bucket and set it in the sink. Place the filter on the counter so that the lower valve-stem hangs over the bucket at the edge of the sink.
4. Turn the lower valve stem counter-clockwise and point it down into the bucket.
5. Open both valves and empty the filter’s water into the bucket.
6. Now, close the bottom valve. Then, undo the clips and lift off the lid and set it aside on a towel for now.
7. Take the bucket of filter water out of the sink, leaving the valve stem pointed into the sink, open the bottom valve again, and slowly pour the water into the top of the canister. The water will come three times dirtier than the first time. This is because you are back-flushing the filter media - sending the water in the opposite direction that it normally flows.
8. When the filter has emptied, close the bottom valve again and turn it clock-wise back up.
9. Now, is a good time to check the top layer of filtering media (it’s right there), EhfiSynth, and see if it might need replacing. Also, it’s a good time to pull out the instructions and follow the procedure for cleaning the impeller. You kept your instructions, didn’t you?
10. Wet the O-Ring, and slide it over the bottom of the lid and press down.
When you’re done, take the filter back, hook up the double taps, open the bottom valves first and then the top valves. The filter should fill up again on its own (no need to start the siphon manually). When it’s full, plug it in. You’re done.
Meanwhile, three more months later…
By now it’s time to change out about one-half to two-thirds of the EhfiSubstrat biological filter media. EhfiSubstrat is made of sintered glass beads which makes it very porous, providing excellent surface area (18,335 sq. ft. / U.S. gallon) for nitrifying bacteria to thrive. The bacteria adhere to the glass better than any plastic or ceramic media. All this is why EhfiSubstrat is just about the best biological filter media on the market. However, even this will clog-up over time and need to be replaced. You only change out part of it so that the old media will seed the new media with bacteria without subjecting the fish to another cycle. The easiest way to do the change-out is as follows:
Call this The Second Half Maintenance.
1. Unplug the filter, close all the valves, and disconnect the filter.
2. Drain the filter as you did for the quick maintenance above. (Leave out the bucket this time and let the water go down the drain.)
3. When it’s empty, remove the lid and set it aside with the O-Ring. Now, lay out an old bath towel on the kitchen counter.
4. Remove the EhfiSynth media (It will more than likely need to be replaced.) from the filter. Now, you want to pour the media slowly out of the canister into a row on the towel. The row should be in segments of EhfiSubstrat, a wad of EhfiFix, and EhfiMech.
5. While the canister is empty, it’s a good time to rinse it out thoroughly in the sink with tap water. Do not use any chemical cleaners! Do not run it in the dishwasher!
6. Set the canister upside down over the towel for a bit while you rinse out the EhfiMech (ceramic rings) just like you did when you first set up the filter. Afterwards, go ahead and put the EhfiMech back into the canister.
7. Thoroughly rinse out the EhfiFix (green stuff or blue pad) in the sink and place it back into the filter.
8. Since you’re rinsing stuff, why not rinse out the new EhfiSubstrat. Remember that this should be enough to replace ‡ to 2/3 of the original EhfiSubstrat.
9. Now remove ‡ to 2/3 of the old EhfiSubstrat pile and throw it away (Ed. note: you can also boil the ehfisubstrat in water, with a splash of bleach if you want it to get nice and white again, dry and save for future use). Mix the remaining media with the new and place it into the filter.
10. Put your EhfiSynth (white, cotton stuff or pad) on top.
11. Now is a good time to clean the impeller.
12. Wet the O-Ring, and slide it over the bottom of the lid and press down. Lock the clips into place, and reconnect the filter as you did before. The siphon should start by itself after you open the bottom valves and then the top valves. When it’s full, plug it in.
13. Once it’s running again, give it a pat on the pump-head and say "See you in three months."
And now…
Three months from this point, repeat "The First Half Maintenance" - the back flush of filter media. And three months after that repeat "The Second Half Maintenance" - EhfiSubstrat replacement. Notice that you’ve only replaced EhfiSubstrat and EhfiSynth. You don’t have to replace EhfiFix or EhfiMech until they are completely worn out. Just rinse and reuse. You may, at some point during the year, use some carbon for some reason or another. If you need to, place it in a convenient spot in the filter. For example, you could exchange the EhfiSynth on top with it. Just remember that it doesn’t take long for the carbon to achieve the desired effect. So don’t leave it in too long. A couple of days to a week should suffice. If it doesn’t, then you need to have a look at your other maintenance practices. For example, are you overfeeding the fish (very easy to do and the leading cause of fish death!)? Are you doing regular partial water changes. 25% every two weeks (recommended) or 50% every four weeks (that could be pushing it). Upkeep on these two factors alone may eliminate the need for carbon at all.
After the first year, you should check and see just how much it cost you to run your Eheim Filter. Then, compare that with what it would cost to run other types of filters. I think you be surprised at how much you saved in time and money. __________________
