Intake & Return Canister Hose Length

[jimwg]

en I first set up a canister filter it was having some difficulty with "hiccups" and sputtering until I shortened the intake hose removing the loop there after which my canisters have always ran great, even though I've never worried about any loops in the return hoses figuring they would reduce the pump's fight against gravity by breaking up a direct shot nearly straight up. I watched this video today
by Ben Ochart in which he stated exactly the opposite. I left a comment regarding this on the video even though it's more than a year old. I really think he's dead wrong about this.

 

[seangee]

I agree. Short as possible, straight up and straight down and they work every time.

 

[jimwg]

I agree. Short as possible, straight up and straight down and they work every time.

I don't really have a loop in my return hose, just a dip then straight up to the outlet. What I don't agree with is the video poster saying that it matters more that the return hose be straight up than the intake hose. This hasn't been my experience. I assume having both hoses as short as possible works fine but that's not what the video poster was saying, he said the intake hose wasn't as much of a concern, and it wasn't what I was saying so I'm not sure who you're agreeing with.

Another Ben Ochart video was very helpful to me though. When I set up my new canister filter I retired the several old filters I'd been running. But then there was hardly any surface water motion and the fish seemed to be gasping often. I watched this video

of his in which he talked about lack of surface water motion can lead to oxygen deprivation issues. So I replaced my trusty Marineland HOB loaded with polyfloss creating a nice waterfall and I'm already seeing a difference in the fish. I really should have remembered this, in past I've always had a lot of surface water motion from the multiple filters I used.

 

[Byron]

I agree with his advice to keep the hoses, especially the return hose (returning water from the filter back into the aquarium), as long as needed but not excessively longer. The physics make sense, and the return is working against gravity.

I had three Eheim Pro II canisters running for 20 years. On one tank I had to place the canister at one end, not under the middle, so the return hose ran some 6 feet. I did notice a decrease in pressure compared to the canister that could sit mid-tank with equal distant hoses.

One thing I liked about Eheim was that you could choose the length of hose you need, and have it cut; it was not pre-measured like the Rena Filstar I bought. I could not have the intake and return at opposite ends because the return hose would not reach that far, and I had to place the canister at one end of the tank since it would not go under the tank (not enough height, it was a 5-foot tank with an iron stand).

 

[seangee]

What I don't agree with is the video poster saying that it matters more that the return hose be straight up than the intake hose.

If you get air trapped in the return hose after cleaning it is much harder to clear if you have any downward angle in the hose. The bubbles float up to the highest point and then ...
On the intake hose it causes problems for priming but I only ever do this when I clean the hoses - which is not nearly as often as I clean the media. I keep the intake low enough in the tank that it cannot get air in it - even for a 75% change