PRTurboZX3, I've got a pair of Magnum 350's on my bigger tank, and I've never used the Siphon Kleen into the filter canister.
Instead, I've just started a siphon into a bucket and use the Siphon Kleen to clean the gravel, just like any ordinary gravel vac. An added benefit is that I do a water change at the same time. I think most people who vaccuum gravel do it this way.
The Eheim Sludge Extractor is pretty pricy for what you get. I hooked up an old Penguin 1140 powerhead to some 3/4" PVC and a hose-end barb that connects to my gravel cleaner, and a foot switch made for Christmas lights. I had to mill the inside of a 90-degree slip-to-slip 3/4" PVC elbow to get it to fit around the impeller housing of the Penguin powerhead.
The powerhead sits in the bottom of a 5gal bucket, and my down-pipe sticks up out of the bucket. It requires me to first start a siphon going from my Siphon Kleen to get it to work, but when it does, boy does it ever pull stuff out of the gravel. Once the bucket is full, I stomp on the switch to shut it off, turn off a shutoff valve I have on top of my gravel cleaner (I stuck the Siphon Kleen tube into the end of a Drs. F & S gravel cleaner, since it has a shutoff valve). I then pick it up and pop it into a spare bucket, and empty the full bucket. Stomp on the switch to get it running again, and keep vacuuming.
Yes, it's a real Rube Goldberg (or Heath Robinson for our Commonwealth friends) affair, but it works great.
v/r, N-A
