# Sunsun 304b rattle.



## DayOlder (Jul 12, 2014)

I do not use rings or balls in my sunsun but if you haven't checked the impeller I would suggest you check that is properly sealed. If the 304 is like the 302 it is easy to installed the impeller without it being fully sealed.


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## cgorges (Sep 9, 2014)

+1 Ive done that. If the piece tha tholds the impeller in isnt fully locked it will rattle.


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## jsanchez (Mar 4, 2015)

Thank you guys as soon as I get home I'll check the seal. I haven't touched it and it was pre-installed at the factory but it's Chinese so odds are it was sealed poorly.


Edit: Well I took the impeller cover off and placed back on but it still makes the same noise. Since it was still loud I added some vaseline to the plastic stick the impeller slides into and still noisy. I'll remove all media and see if it makes noise still to single out the impeller as the main cause.


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## jsanchez (Mar 4, 2015)

So empty or not the filter rattles. It's not a strong rattle, and the filter is working well but I can hear it while trying to sleep. Tank is in my bedroom. Anyone know if this filter comes with a warranty? Nothing that came with the filter says it does.
Kinda sucks considering how every review I saw mentioned how dead silent this filter is.


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## FatherLandDescendant (Jul 24, 2014)

Sounds like the impeller blades knocking the retaining plate, I had this issue with a MarineLand C series unit. I just made a small shim with a rubber band to hold the impeller up inside the housing and keep it from riding down the shaft so it doesn't rest on top of the retaining plate. Trick is to keep it off of not only the retaining plate, but also the inside of the impeller housing, allowing it to rest/float between the two surfaces.


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## jsanchez (Mar 4, 2015)

I'll get on that first thing in the A.m. Impeller does have a lot of room to go up and down the shaft. Hopefully this solves it. I ordered two of these for my 40 breeder so I hope the second one isn't anywhere near as loud.


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## jsanchez (Mar 4, 2015)

Got my second sunsun in and it also rattles, but not as bad. So I'm just hoping that it'll "break" in and fix it self. Im thinking it might be trapped air but not mater how I shake the filters I can't get anymore air out.


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## Linwood (Jun 19, 2014)

I have four of the 404B's, and the only time I have had a rattle is once when the impeller cover fell off (yes off, not just loose). It will also rattle if I stifle the flow too much (one of them has a ball valve to reduce flow), and of course if it gets air in it. 

The simple way to check for air is wait a while, let it rattle a while, then shake. If air comes out each time you do this, you have an intake leak that is building up air. If not, look elsewhere.


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## OhioTank (Mar 11, 2015)

I have 2 304B on my 75 and aside from rocking it to get the air out, sometimes it just takes a day or two to get it all. I don't know how long yours has been running. I also had the impeller issue on my C-360, if it has been hitting the housing you should be able to see marks on the retaining ring or the housing and try to adjust so it doesn't hit. These are great filters for the $$$$$ but are not perfect! Mine are practically silent!


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## jsanchez (Mar 4, 2015)

I'll give it a week before I start to "worry". Some of the return pumps I've used on my reef tanks would be noisy at first, but once they grew some film on the impeller they where dead silent.


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