# Fluval 306 canister filter making noise/vibration



## Watever (Aug 16, 2015)

I bought the filter 2 months ago on black friday with all new tank, heater etc, and started my tank a week ago. Currently cycling with new plants / no fish.

The filter is suppose to be quiet and that's the reason I bought it.
I needed it to be quiet, my girlfriend didn't want me to start a new tank with HOB because of that.

It's now been running for nearly a week and there is still noise. More like vibration.
I did everything to be sure there was no "air" in the filter or tube. I even reduced them.
There is rubber feet under the filter. But it feels like it's coming from the impeller head. I looked at the head, there seems to be some "loose" on the impeller but cannot say if it's normal or not as I have not seen any others.

The noise get out of the cabinet and we can hear it clearly in the living room and even upstairs at night.
Make watching the TV impossible.

I took two video with my phone. A bit difficult to catch with the microphone but you can hear and understand.










I also sent the video to fluval support. Hopefully I/they can do something about it.
But some people here might have seen or did something to fix this issue already.


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## ipkiss (Aug 9, 2011)

Yea, that's definitely an abnormal amount of noise. Hopefully fluval can help you out.

Apologies for not having ideas to fix.


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## Mike A. (Jan 6, 2018)

Agree, something's not right. 

Might pop the impeller out and see if it looks OK and that the cover over it is seated properly. 

Make sure that you don't have loops in your tubing that might be trapping air. Try pumping the primer rod a few times while it's running and see if you get air bubbles out of the return. If so, then there's air inside which can make it rattle.


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## Watever (Aug 16, 2015)

ipkiss said:


> Yea, that's definitely an abnormal amount of noise. Hopefully fluval can help you out.
> 
> Apologies for not having ideas to fix.


Thank you, I am happy to know this 

I figured out the issue. 
I am an engineer, so I removed and checked the design a little.
It's a simple nice design that should not make noise. It's all magnetic and should work nearly quite fine.
The impeller is slightly loose and it is hitting plastic housing somehow. Cannot verify if it's all the blade or only one. Or it might be imbalanced. Hard to verify as it need to be running in correct position (motor upside down) and I don't want to run it dry for more than 1-2 seconds.

Will see what Fluval says and I also spoke with the store. I might take it all to them to check it with them. But I don't think they can do more, except help me with the oem.


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## Mike A. (Jan 6, 2018)

Watever said:


> The impeller is slightly loose and it is hitting plastic housing somehow. Cannot verify if it's all the blade or only one. Or it might be imbalanced. Hard to verify as it need to be running in correct position (motor upside down) and I don't want to run it dry for more than 1-2 seconds...


The red cover over the impeller is what holds it in place. Might not be seated right. It's easy to open up. Clips to one side. 

From there check the impeller. Pulls straight out. It rides on a ceramic shaft and there should be a rubber bushing at the top.


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## Shazwazer (Jan 28, 2011)

Those things are pretty easy to tear down and all the parts are replaceable. Tear it down and see what looks weird.


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## Watever (Aug 16, 2015)

Mike A. said:


> The red cover over the impeller is what holds it in place. Might not be seated right. It's easy to open up. Clips to one side.
> 
> 
> 
> From there check the impeller. Pulls straight out. It rides on a ceramic shaft and there should be a rubber bushing at the top.


Exactly,
The rubber seal on the shaft is there and same on the impeller cover. Shaft not broken.
Everything seems good but noise is definitely coming from there and my judgment is unbalanced.
The impeller holding might be loose on the rotation, not sure on the design. 

Sent from my LG-M470 using Tapatalk


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## Watever (Aug 16, 2015)

I took it to my local fish store as they suggested and they verified it.
Based on them, it's quite and doesn't have a problem. There is way more ambiant noise out there. It seemed to do less vibration when touching it but difficult to say.
They opened and verified it mechanically. They didn't see any issue either. 

They said the first iteration of theses filters (end with 6), few years ago, had few units where the impeller gasket (red) would pop or not sit correctly creating lots of vibration, but not the case with this one.

So I reinstalled it and will check what I can do.

I squeezed sponge between the filter and the cabinet wall, instead of leaving air. Seems to help but might just be my personnal feeling and not the reality as I don't have equipment to measure the sound.


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## ipkiss (Aug 9, 2011)

Huh. I'm sorry to pile on some more bad news for you. So I know I said it sounded abnormal originally but it seems that I better eat some crow. I tried to take a video of my unit for you to show the store but it turns out that they may be right. My unit is a few years old but the sound is pretty much on the level that you showed. Guess all these years it just melted in the background. Then again, for many years I ran HOBs with splashing water.






There's something about these videos that seem louder than they really are. So I measured it with a couple dB apps. It hovers in the 60s when you put the phone's mic right above the in/out tubes and in the 50s about a foot in front of it.










Probably see if you can swap it out for an eheim or something if you're after more silence  

I hope they understand that you didn't mess with it since Black Friday and it's essentially new. I have that bad habit too. Buying stuff and not using it until way after the warranty period. Maybe you can off it to someone in the hobby or build a sound baffle around it. :/ Good luck.


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## Watever (Aug 16, 2015)

I don't think another filter from another company will be much better.

I will try to reduce the sound coming out of the cabinet. Mostly by closing the back and adding some anti vibration under the filter. Just by lifting the canister with my hand help, but it's kind of normal cause my body help dampening it out.
The sponge under aren't solid enough to keep the canister level so it's too dangerous.

I will play with it next week and see what I can do with different materials from the hardware store.

Bump: Thank you for the help !

When I get a working solution, I will post it back for others.


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## stevewb (Nov 10, 2018)

Mine was noisy initially so I noticed when I clip the impeller cover back into place it doesn’t seat all the way so I press around the edges to get it down and it quotes down a bit


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## Watever (Aug 16, 2015)

stevewb said:


> Mine was noisy initially so I noticed when I clip the impeller cover back into place it doesn’t seat all the way so I press around the edges to get it down and it quotes down a bit


That's not supposed to be. You should be able to get it replaced or that part fix.

My issue is with the motor vibration in the head that resonate in the cabinet. 

What I did is to add fiberglass isolation inside the cabinet. It works but I only covered the back.
I am planning on another solution as it takes too much space. Probably some moving heavy carpet with some fiberglass behind, mostly on the back and side. Base and top will only have carpet or something like that to reduce some of the vibration sound. 

Sent from my LG-M470 using Tapatalk


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## Redski (Oct 12, 2020)

I'm aware this is an older post - but I found the solution for the same issue I had that was described by OP. When I disassembled my 207 canister for maintenance and removed the impeller to wash it, the impeller shaft fell out. For the untrained eye the shaft and impeller look like all one part, but once you tip the impeller (to wash it) it will slide out. If you reassemble without the shaft nothing is holding the impeller for bouncing around inside the housing which causes the rattling. 

This is a link for a replacement from Fluval
https://fluvalaquatics.com/us/product/impeller-shaft-and-bushing-for-06-07-series-filters/

this applies to both the 06 and 07 series.


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## BigGinger (Feb 8, 2021)

Glad I found this thread as I was having a similar issue but just sorted it out. Someone went to go ahead and replace the ceramic impeller post because when I was cleaning the motorhead the ceramic rod just fell out in two pieces. I figured that was what was causing a rattling noise, but when the part arrives and I replaced it the rattling noise continued. Today I got completely fed up with the noise so I took the entire assembly apart and found that the magnetic housing around the ceramic post had a crack in the protruding top.


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