Different lengths for intake/outflow pipes?

[Lusus_Naturae]

I am running a Rena XP4 on my 125 and I currently have it set up with 3/4 inch drinking line pex with a few small sections of the original plastic tubing worked in to connect parts. I'd like to clean up how it's set up sometimes this spring, but I have a couple questions.

The current plan is to continue to use 3/4 inch inside diameter pipe, so no change there. I have the canister under the stand, and I have a couple clearance issues to address towards to rear wall behind the tank but this rebuild should make it work better not worse. When I threw this filter together I was under a time push, so I measured the long section of pex for the return first and cut the intake section to match length. Currently both sections are matched in length within one inch. I prefer the intake in the middle and the spray bar on the side pushing water across the tank - which means if I was to make it look ideal I would end up with a shorter intake pipe and longer outflow pipe.

Is this an issue? Am I better off just bending the longer intake pipe to fit better and clean up the design that way (I am using sharkbite right now which bends under heat)? I have some people that swear on only using even lengths, and other that say it should work fine. Has anyone noticed a difference between the flow of a system with 90 degree elbows and a system where flex tube or bent pipe would make the same angle a 90 curve instead - creating a smoother transition?

 

[deeda]

The general recommendation by aquarium filter manufacturers' is that the intake and output hoses are of equal length. But of course that length is usually not followed by some fish keepers. I usually have the input and output lines on the same side of the tank but that is because I am using two canisters on each tank. I don't know if three extra feet of tubing is going to cause you any problems, you could always try it and post your results in this thread.

I prefer not to use PVC 90° fittings to transition over the rim of the tank unless you use the next larger size of fittings. If you can get a PVC to PEX transition fitting, try and make your own J-tube if you like a DIY project.

I have been making my own PVC J-tubes for the Eheim 2260 filters because I don't like the ones provided with the filter. I just fill the PVC pipe with fine sand, cap the ends and use a heat gun to heat the pipe in the area I want the bend to be, being careful to keep rotating the pipe so the heat is spread evenly around the pipe diameter. Once the pipe starts to flex slightly, I slowly bend it around an empty soup can until I get the J shape desired. Empty the sand from the pipe, lightly scuff the pipe surface and spray paint it black, using Krylon Fusion for plastics. I let it cure for a couple days, rinse it out and put it in the tank. Works great, looks great and is a simple project BUT please use heavy leather gloves as the PVC does get hot.

 

[Lusus_Naturae]

Soup can is a neat idea. I also wouldn't have thought to use sand like that either, will definitely have to do that on the rebuild. To bend the pex we simply heated it up over the gas range top and turned it, not ideal but got it done fast. We didn't get any collapse in the tubing but we took easy angles on it that night and on this clean up project I would like to tighten it up.

We wanted to get it done fast that night and hacked it together, it works fine (which means I'm going to get lazy about fixing it) but it doesn't look nice (which means I'm going to get bugged to fix it). We used the oem spray bar and j tube outflow, and connected a small section of oem tube to it, that tube connected to the pex which ran down the side and under the stand where another small section of oem tube was used to connect it to the outflow neck. We are currently using the oem intake j tube, although I have been made aware that the blue color sticks out, so that may have to be replaced. The intake has another short section of tubing that joins it to the pex - and here's where it gets interesting. Because this side needs to be shorter, we have this section twisted into a spiral to shorten it up, and then connects again to a small section of tube to the intake neck. The spiral runs vertical so there's no air build up in it. I'll doodle up some diagrams of it too, that usually helps me find the flaws.

 

[Lusus_Naturae]

If I need to keep exact length of pipe and clean it up, I came up with the design below which is a cleaned up version of what I'm running with the tighter spiral on the intake (mine is haphazardly running in a wide loop which doesn't fit well. I may also recheck if I can move it over to the left side of the tank - it was set in the middle because both doors open without a divider in the middle allowing me to pull it out with the tub it sits in if I need to. If I move it to the left I will have to unhook it before I move it out through the middle anyhow so using the middle for storage will be a pita. The filter on the right is an Emperor 400 which I plan to leave on there as well, nothing like overfiltering a tank.

 

[deeda]

I think you can just remove that spiral section of hose from the intake section.

 

[Lusus_Naturae]

That's what I was hoping I could do.