New FX6 making sloshing water noise

I've had an FX6 for about a month and a half now on a 75g tank and I struggle to get it to purge air, it makes this loud water sloshing noise. (Purchased new on 2020-12-22.)

It seems to work still but the noise is annoying and I worry it will effect the longevity of the filter.

Things I've tried to fix the problem;

-cutting the lines to the bare minimum length, no kinks at all.
-removed media
-rinsed out sponges
-filling it to the top 100% before plugging it in
-switched intake and output hoses
-turned off bubbler no where near intake.
-shake hoses with it on
-Made sure the connections are well below the water line
-have output hoses angled upwards
-Checked connection between hoses and filter/output nozzle and intake strainer
-Checked the O ring in the lid seal
-Priming it with the output hoses above the water line

At one point I just shook the canister with it on and it burped out some bubbles (super hard to do under the cabinet while full) This was the only way I was able to get it to purge brand new.

Tonight I did a water change and it's back to sloshing and even shaking it hasn't worked. I'm at a loss, did I just get a defective unit? When I have been able to get the air out it runs silently. I was able to get it to run silently this time by wedging a piece of carboard under one of the legs so it's at a bit of an angle (aquarium is level... I checked.)

I tried contacting Hagen customer support and they were less than helpful, didn't read my email and said it sounds like a bad impeller (I find that hard to believe) and to return it to the store (can't due to being locked down right now). I just got this tank cycled 2 weeks ago and don't want to go through the hassle of changing out the filter and losing my BB if I'm just doing something wrong.

I also find it hard to believe that the FX6 would have such glowing reviews if it was this hard to prime every time you did anything to it.

Any advice would be appreciated.

Thank you.

 

I would return. Mine hums but that’s about it and it’s going on 2 yrs old. If worried about the cycle you could buy another than remove all the media from yours (just the media) add to new one than return the old one for your money back. Now by keeping the media you have the bb and the cycle. I’d also return the cut hoses and use the new ones. Mine runs fine even with the slack in the hoses.

 

Same here, to be honest I think my FX6 is quieter then my other canisters and HOB.
It also should shut itself down once a day to prime the filter out.
I would return it for a new one.

 

Thank's for the replies guys, I guess I will return it. I called the petsmart I bought it from this morning and they said I could keep the filter media and return just the canister and hoses for a new one once the lockdown has ended (I'm hoping in the next couple weeks!)

I'm just curious when you have to do maintenance do you have to do anything special to get it to prime (like having the output above the water line) or does it just automatically prime when you start it up?

 

Thank's for the replies guys, I guess I will return it. I called the petsmart I bought it from this morning and they said I could keep the filter media and return just the canister and hoses for a new one once the lockdown has ended (I'm hoping in the next couple weeks!)

I'm just curious when you have to do maintenance do you have to do anything special to get it to prime (like having the output above the water line) or does it just automatically prime when you start it up?

I clean my 2 FX6 filters every 3-4 months, just refill with water to the top, put cover on then turn on the ( in ) valve first, then wait a few seconds and turn on the other. Plug in and good to go.

 

With mine I have to add 2 gallons of water to it to start it up. That’s it. Mine starts right up runs for 12hrs than stops for a minute to purge the air in it and restarts.

 

I've got an FX4 and never had this issue either. Very strange.

Question, how much water do you fill into the canister body before putting the lid back on?

I try to fill our FX4 as high as possible, install the lid, then pour some water down the intake to top it off before installing the valve block back on..

Also, did you try unplugging it, letting it sit for a minute, plug it back in for a few minutes, then repeat a few times?

A min after it's plugged back in, FX's will self-turn off to bleed out air then turn itself back on again after a min.

Maybe it needs to do a few cycles of that.

Also, it's possible it's sucking in air somewhere.

Here are some possible scenarios for this:

* air stone too close to intake: Move air stone to opposite end of tank

* connection between intake tube and hose not airtight: Re-check connection points for proper fit

* connection between hose and intake valve not airtight: Re-check connection points for proper fit

* valve block connection is not airtight: re-check connection point and make sure everything is seated properly. Visually inspect o-rings. Re-lube with food grade safe silicone grease

* filter lid not properly sealed/seated against canister body: pull lid off and inspect oring/gasket between lid and body. It may have a kink/twist in it our something fell in between the mating surfaces. Visually inspect and clean with q-tips. Re-lube o-ring with food grade safe silicone grease

* bottom drain plug is not properly tightened: Remove and inspect o-ring/gasket. Clean and re-lube with silicone grease. Fasten drain plug back on and ensure proper fit.

All of these scenarios could possibly contribute to air entering the canister.

Let us know if any of this can remedy your situation.

 

Not sure if filling to the top is recomended. Instructions say 2gal open intake first than output to start flow. If fill your not going to get that vacume flow through the filter.

 

I don't clean my FX very often. I know I fill my other canisters like that though.

I agree with 86 ssinit. Best to follow the instructions, Fluval knows what they are doing!

 

I had a similar issue with my FX6 and realized eventually I just needed to add a little more water to the canister. It says 2 gallons but I always put a little more in and boom just like that issue solved.. best of luck!

 

I've got an FX4 and never had this issue either. Very strange.

Question, how much water do you fill into the canister body before putting the lid back on?

I try to fill our FX4 as high as possible, install the lid, then pour some water down the intake to top it off before installing the valve block back on..

Also, did you try unplugging it, letting it sit for a minute, plug it back in for a few minutes, then repeat a few times?

A min after it's plugged back in, FX's will self-turn off to bleed out air then turn itself back on again after a min.

Maybe it needs to do a few cycles of that.

Also, it's possible it's sucking in air somewhere.

Here are some possible scenarios for this:

* air stone too close to intake: Move air stone to opposite end of tank

* connection between intake tube and hose not airtight: Re-check connection points for proper fit

* connection between hose and intake valve not airtight: Re-check connection points for proper fit

* valve block connection is not airtight: re-check connection point and make sure everything is seated properly. Visually inspect o-rings. Re-lube with food grade safe silicone grease

* filter lid not properly sealed/seated against canister body: pull lid off and inspect oring/gasket between lid and body. It may have a kink/twist in it our something fell in between the mating surfaces. Visually inspect and clean with q-tips. Re-lube o-ring with food grade safe silicone grease

* bottom drain plug is not properly tightened: Remove and inspect o-ring/gasket. Clean and re-lube with silicone grease. Fasten drain plug back on and ensure proper fit.

All of these scenarios could possibly contribute to air entering the canister.

Let us know if any of this can remedy your situation.

Thank you for your detailed response!

I've tried filling it with only 2 gallons and I've tried filling it to the top with no noticeable difference in the sloshing noise. I haven't tried pouring water down the intake tube though.

I've also tried unplugging it and plugging it back in several times.

I ordered some food safe silicone grease that should arrive tomorrow, I'm going to take everything apart, recheck all the connections and try one more time before exchanging it.

Strangely enough it runs silently with no sloshing if I wedge carboard under one leg making it sit uneven... not sure what the long term effects of this would be though.

I'll report back once I've tried all the steps above, thank you!

So I ended up having some plumbing silicon in my garage so I tore down the FX6 and tried out the following;

-Intake Outtake tubes in aquarium connection - Removed checked/ greased

-Removed drain valve - Checked O rings lubed

-Checked the hose clamps on the intake and outtake tubes - retightened

-Removed Lid - Checked O ring lubed

-Removed motor assembly checked O rings, lubed

-Took apart media baskets made sure everything was level and assembled correctly

- Put 2.5 gallons of water into the canister, measured it...

-Drained 30% of the water in the tank so the output was above water line

-Opened up intake let sit for 10 seconds, opened output and plugged in... moment of truth.... still sloshing. I did notice with the output above the water line the air purge was much more violent.

-Waited about 15 mins still sloshing, tried cycling it a few times... still sloshing I have attached a video.

 

Video would not play for me.

Were you able to get anything more out of Fluval to troubleshoot the issue?

 

This happens with mine after a water change when there isn’t enough water in it. Maybe add a bit more water. If that doesn’t help it then it might just be defective.

 

Video would not play for me.

Were you able to get anything more out of Fluval to troubleshoot the issue?

No they sent me a link to the website with the troubleshooting steps that I had already taken and said return it if the steps don't work so that they can assess whether it's defective themselves under the 3 year warranty.

I tore it down again today for one last final try and inspection and can't see anything wrong, all the O-rings are intact and lubed. I tried moving the intake and output up and down an inch to see if that would make a difference but no dice.

I also tried filling it a bit more and a bit less but still have the sloshing noises. At this point I give up, I bought this as I thought it would be less maintenance and have tore it down 8 times this month haha. Stores in my area open up again next Tuesday so I'm hoping I can exchange it and have better luck with the new one.

 

Just thought I'd post an update, I was finally able to exchange my FX6 today. It was nice to be able to go into the store again after 2 months in lockdown and see the fish!

Shout out to my local petsmart they were surprisingly awesome, I explained the situation and provided them with the emails I had exchanged with Fluval/Hagen and they exchanged it no problem. They let me keep the cycled media as well which I was super happy about!

To try and preserve as much of the bacteria as possible I emptied the old canister water into a 5 gallon bucket and put the sponges and bioballs etc in there with a bubbler as this took around 1.5 hours total.

So, filled with lots of anxiety I went to work setting up the new one from scratch, I took out the new media and put in my cycled media, I was worried that this was somehow the problem after all this but obviously needed to keep my BB.

The moment of truth; I opened the intake first then the output, plugged it in and... it just worked! No sloshing, it just runs silently!

I guess I was just unlucky and got a dud.

 

Glad it worked out for you. Plus you’ve got all the extra media!!! Good luck with it I’m happy with mine!

 

I took mine apart yesterday to clean it and I’m so happy no slushing once reassembled! Enjoy your quiet machine, I also love mine!!