Good replacement for fx6 ?

[anewbie]

I have an fx6 on a 120 (48x24x24) and it goes rocking 24 hours a day (what it does to remove air); support sez replace the seals; so i replaced all the seals; it still rocks 24 hours a day. 

Any suggestions for a good replacement ? Since this is a 'trash' aquarium i'd consider either canister or hob but i want pretty good filtration as it has some grow out angels (14); left over plecos (5) and breeding krobia (5).

[mynameisnobody]

IMO, the only replacement for an fx6 is an fx6. If you don’t want to spend that much then go with another canister or HOB. 

[NOLANANO]

If you are looking for a budget cannister filter I have a Sun Sun and I've legit never seen clearer water than I have in my 75G.  Everyone that I hears I have a sun sun tells me I need to upgrade because it will fail on me but its been going strong for going on 3 years now without any issues.

[mynameisnobody]

@NOLANANO after my 3rd sunsun sprung a leak, I vowed never again. The O rings on those things are brittle. If you got years out of it, then that’s great, but you’re more the exception than the norm. 

[NOLANANO]

On 1/25/2024 at 9:20 AM, mynameisnobody said:

@NOLANANO after my 3rd sunsun sprung a leak, I vowed never again. The O rings on those things are brittle. If you got years out of it, then that’s great, but you’re more the exception than the norm. 

Maybe I have been lucky but my secret has been to open the lid as seldom as possible. I just cleaned the filter last week for the first time in 18 months. I have a heavily planted tank so water quality was never an issue. If you don't mess with the seals, they don't break. Or maybe I am full of it and have just been lucky.

[mynameisnobody]

That’s excellent and your hack seems to work. Personally, I would hate to own something that I know I shouldn’t service because it may cause problems. But if it works then it works. 

[anewbie]

Well the fx6 is only around 3 1/2 years old so it didn't last as long as your sun sun; something to consider.

 

[Pepere]

Well, air is getting in somewhere…have you checked all of the hose connections as well?

[nabokovfan87]

On 1/24/2024 at 6:41 PM, anewbie said:

I have an fx6 on a 120 (48x24x24) and it goes rocking 24 hours a day (what it does to remove air); support sez replace the seals; so i replaced all the seals; it still rocks 24 hours a day. 

vibration or like.... the whole thing is moving / shaking?  What I mean is, if you had your hand on the lid or pump itself do you feel the vibration or is the issue related to something causing say... the pipework to shake and that reverberates all the way down to the canister itself shaking around (like a washing machine imbalanced)

Basically the FX replacement is ADA Superjet / stainless steel canisters or you go to EHeim. 

 

Edited January 25 by nabokovfan87

[anewbie]

On 1/25/2024 at 5:19 PM, Pepere said:

Well, air is getting in somewhere…have you checked all of the hose connections as well?

I purchased their 'maint' kit and replaced all the seals. There are only two hoses and if their is no leaking.

[anewbie]

On 1/25/2024 at 5:30 PM, nabokovfan87 said:

vibration or like.... the whole thing is moving / shaking?  What I mean is, if you had your hand on the lid or pump itself do you feel the vibration or is the issue related to something causing say... the pipework to shake and that reverberates all the way down to the canister itself shaking around (like a washing machine imbalanced)

Basically the FX replacement is ADA Superjet / stainless steel canisters or you go to EHeim. 

 

Well that superjet looks impressive; but it is of course 5x the cost of an fx6. The vibration is what you expect when the filter tries to kick out air; the hoses shake and it makes a noise but the vibration comes from the canister filter motor - there is nothing around it that generates any vibration 'cept for a very small air pump. Hum - here is a video:

 

[Pepere]

On 1/26/2024 at 7:50 AM, anewbie said:

There are only two hoses and if their is no leaking.

I would look over the entire suction side.  You can have an air leak into the stream with no water leak out.  You would only see a leak which might only be a seep, when the pump is off and then only at lower elevation where sufficient head occurs.

 

regardless, if air is purging out, it is getting in somehow.  I am assuming there is no air stone near the water pickup…

 

have you lubricated the seals with silicone grease?checked mating surfaces for nicks, cracks deformation?

[nabokovfan87]

On 1/26/2024 at 5:09 AM, anewbie said:

Well that superjet looks impressive; but it is of course 5x the cost of an fx6. The vibration is what you expect when the filter tries to kick out air; the hoses shake and it makes a noise but the vibration comes from the canister filter motor - there is nothing around it that generates any vibration 'cept for a very small air pump. Hum - here is a video:

Basically it's straight up pumping air. So something is allowing air in at a very high rate.

Can you show the input / output? It's not the actual pump or canister it looks like.  Emailing fluval that video might help you out as well get to the right path or let them know there's a product issue.

Unfortunately the intakes on the fluvals are pretty cheap. They aren't very high quality and you could have some weird issues there.  Also verify the input is on the input side and output is on the output side. We all make mistakes, just have to double check it.

The only thing that seemed weird at first was the bend radius on that right tube. As the video continues, it looks ok and it was just a weird angle visually.

Random question, have you ever used the maintenance line to clean the filter or do you just drag it out filled up when you clean it? Is the cap on fully and tightly sealed?

[Galabar]

I wonder if shortening that hose (removing the slack) would help?

[Pepere]

On 1/26/2024 at 1:20 PM, nabokovfan87 said:

Also verify the input is on the input side and output is on the output side. We all make mistakes, just have to double check it.

Yep.  Last time I serviced 1 of my 207s and cleaned all the tubing and spray bar etc… i reversed them.  And wondered why one hose was the right length and the other one was 8 inches too long…

 

hint, if this ever happens to one of you check to make sure you are hooking it up right before whipping out the utility knife to shorten the hose…. Like I did….

 

Then, the filter would not prime or run….

 

And when the brain cells woke up and I reconnected everything… well one hose was annoyingly 8 inches too short….   Now I might not always be the brightest, but I am pretty strong on keeping back up parts on hand for emergencies… I had a spare ribbed hose set…

 

I measured twice, cut once and hooked it all up right and it primed wonderfully and ran like it should….  
 

Then I went and ordered a replacement hose set….

[anewbie]

On 1/26/2024 at 12:20 PM, nabokovfan87 said:

Basically it's straight up pumping air. So something is allowing air in at a very high rate.

Can you show the input / output? It's not the actual pump or canister it looks like.  Emailing fluval that video might help you out as well get to the right path or let them know there's a product issue.

Unfortunately the intakes on the fluvals are pretty cheap. They aren't very high quality and you could have some weird issues there.  Also verify the input is on the input side and output is on the output side. We all make mistakes, just have to double check it.

The only thing that seemed weird at first was the bend radius on that right tube. As the video continues, it looks ok and it was just a weird angle visually.

Random question, have you ever used the maintenance line to clean the filter or do you just drag it out filled up when you clean it? Is the cap on fully and tightly sealed?

maintenance line? You mean the bottom valve to let water out - yea i've used that. fluval support said they will send me a new one (i think); here are the pictures you asked (this isn't a show tank; i just use it to hold things until i decide what to do with them - right now it there are 5 krobia; 14 angels and 5 pleco; 6 angels are going to the pet shop soon - the krobia are sitting on wrigglers so not sure what to do about that but no one will go near them - they are fierce 😉

 

[Scapexghost]

What about an fx4

[anewbie]

They are on the right side - i have to face the valve on the bottom to the door in the stand; this forces the out to be on the left and in on the right; the two hoses would otherwise cross each other. Looking at the picture you can see they are connected correctly.

 

On 1/27/2024 at 8:19 PM, Scapexghost said:

What about an fx4

Why would i replace a weak filter with a weaker filter ?

Edited January 28 by anewbie

[Scapexghost]

On 1/27/2024 at 8:23 PM, anewbie said:

They are on the right side - i have to face the valve on the bottom to the door in the stand; this forces the out to be on the left and in on the right; the two hoses would otherwise cross each other. Looking at the picture you can see they are connected correctly.

 

Why would i replace a weak filter with a weaker filter ?

I thought the issue was that it was broken not that it wasnt strong enough

[anewbie]

On 1/27/2024 at 8:27 PM, Scapexghost said:

I thought the issue was that it was broken not that it wasnt strong enough

A fx4 is an fx6; i'm presuming the fx6 doesn't actually have air in it but the 'smart motor' has gotten confused; though it could have air in it but it is not obvious where that air is entering. If a design gives me problem (my eheim has never had this issue but it is a simplier design); why would i buy another of the same problematic design. 

20 years ago i had a canister filter that never had an issue for the 5 years i used it; this fx6 is barely touching 3 years. Anyway if fluval replaces it i'll see how that goes. 

Also i would not use anything weaker than the fx6 on that aquarium. I believe the effective flow is quite  a bit less than the rated flow - of course the eheim is probably only 1/2 its rated flow (though it wouldn't hurt if i would clean it; even if that never improves the flow).

[Scapexghost]

On 1/27/2024 at 9:07 PM, anewbie said:

A fx4 is an fx6; i'm presuming the fx6 doesn't actually have air in it but the 'smart motor' has gotten confused; though it could have air in it but it is not obvious where that air is entering. If a design gives me problem (my eheim has never had this issue but it is a simplier design); why would i buy another of the same problematic design. 

20 years ago i had a canister filter that never had an issue for the 5 years i used it; this fx6 is barely touching 3 years. Anyway if fluval replaces it i'll see how that goes. 

Also i would not use anything weaker than the fx6 on that aquarium. I believe the effective flow is quite  a bit less than the rated flow - of course the eheim is probably only 1/2 its rated flow (though it wouldn't hurt if i would clean it; even if that never improves the flow).

Ok if you like your eheim drfinetely get another one of those

[nabokovfan87]

On 1/27/2024 at 6:17 PM, anewbie said:

Intake and all that seems fine.  I'm not sure what is leaking, but something is allowing a ton of air in there.  If it's not the maintenance like then maybe the pump was just damaged somehow.  There's a sponge under the output, right there, I don't think that's causing any issues.  Let's say the pump had a gas bubble or something, turned on to push it out, then that led to the impeller getting damaged or something.  The thing to do next would be to take it apart, verify the impeller and everything is clean/undamaged, then try to either replace the hose or inspect it. 

Beyond that, I don't see any issues.

[anewbie]

On 1/28/2024 at 1:20 AM, nabokovfan87 said:

Intake and all that seems fine.  I'm not sure what is leaking, but something is allowing a ton of air in there.  If it's not the maintenance like then maybe the pump was just damaged somehow.  There's a sponge under the output, right there, I don't think that's causing any issues.  Let's say the pump had a gas bubble or something, turned on to push it out, then that led to the impeller getting damaged or something.  The thing to do next would be to take it apart, verify the impeller and everything is clean/undamaged, then try to either replace the hose or inspect it. 

Beyond that, I don't see any issues.

fluval had me buy and install the maint kit; it included  new seals and impeller so the impeller was replaced last week. The problem has persisted now for about 3 months.

The only thing i can think of is a micro hole in intake ribbon hose but if there is one i can't find it. Btw the sponge filter you pointed out is next to the out-take - can't see how it would impact anything but who knows.

[dasaltemelosguy]

On 1/26/2024 at 5:09 AM, anewbie said:

Well that superjet looks impressive; but it is of course 5x the cost of an fx6. The vibration is what you expect when the filter tries to kick out air; the hoses shake and it makes a noise but the vibration comes from the canister filter motor - there is nothing around it that generates any vibration 'cept for a very small air pump. Hum - here is a video:

 

I have six, FX6’s that have never failed or leaked. They all however have this problem in the video.

But this is not a mechanical problem. It’s an electronic problem.

A power supply for a motor requires that it have a redundancy of voltage so enough is always available for peak demands or in lower voltage environments. The FX6’s voltage regulation was apparently designed for 240 volts so when this is translated for American power, it’s set for 120 volts. However, it's not uncommon to see house voltages vary from 120v down to 110v or even 105v. It is here where the FX6 has barely enough power to keep the motor regulated.

Certain situations cause the filter to require more power; If the flow is restricted, if your house voltage is low, if the outlet is shared by many devices (dropping the effective house voltage), or if you use an extension cord or power strip (also dropping the effective house voltage), etc.  If anything drops the house voltage enough, then this “chugging” can occur.  It’s due to the motor pulling more current on the push cycles of its rotation and the voltage for that momentarily higher demand falls and isn’t available when the motor is at peak demands.

It can also be caused by the filter being run for long periods on lower voltage outlets or if a filter has been dormant for a very long time. Long term operation at less than 120v can deform the capacitors and make them less efficient and cause this chugging. 

But that chugging will go away if you feed that FX6 with about 130vac vs 120vac normal house current.

Often, you’ll find the outlet with a chugging filter will have a voltage drop and read perhaps 105-115v from the drop caused by other loads or that circuit in your house.

However, a chugging filter can sometimes be “fixed” by operating it at a slightly higher voltage for 2-3 days. I’ve repaired two such chugging FX6 motors in this way.

The capacitors in the motor’s power supply tend to assume an internal shape over time from either running at a lower than optimal voltage or if left dormant for months or years. When this happens, the capacitors become less efficient at higher voltages and the overall power to the motor suffers a voltage loss. This contributes to the low voltage chugging problem, but often the capacitors may be ‘revived’ by a technique called “forming”.

A Variac is an autotransformer that can supply typically 130v up or to 150v and any value below this. By plugging the filter into a Variac and running it at 130v or as high as 140v, it “reforms” the capacitors in the motor’s power supply to perform at higher voltages making them perform more efficiently. Flow improves, noise drops, chugging stops and it uses significantly less house power.

I would guess that the Fluval was designed in the 240vac configuration and was converted for American house currents (120V). That would suggest the voltage regulators powering the motor are designed for 240/120 and many American households have less than 120v available on the wall and so that can destabilize the voltage regulation.

The room I have my system in has such a voltage drop. Only about 112v is available so I use a Variac to power my filters and the flow is strong, smooth, linear and consistent.

VARIAC

Since I have six FX6's, I use only one Variac for all 6 such that it made the addition of the Variac worthwhile. Otherwise, a $70 Variac per FX6 could make one think otherwise.

Still, in hindsight, I wonder if a decent pond canister would have been better. They are less than half the price of an FX6 with potentially enormous GPH’s. The submersible pump makes me nervous, but you can’t beat the $/GPH.

POND CANISTER

[anewbie]

On 1/28/2024 at 10:13 AM, dasaltemelosguy said:

I have six, FX6’s that have never failed or leaked. They all however have this problem in the video.

But this is not a mechanical problem. It’s an electronic problem.

A power supply for a motor requires that it have a redundancy of voltage so enough is always available for peak demands or in lower voltage environments. The FX6’s voltage regulation was apparently designed for 240 volts so when this is translated for American power, it’s set for 120 volts. However, it's not uncommon to see house voltages vary from 120v down to 110v or even 105v. It is here where the FX6 has barely enough power to keep the motor regulated.

Certain situations cause the filter to require more power; If the flow is restricted, if your house voltage is low, if the outlet is shared by many devices (dropping the effective house voltage), or if you use an extension cord or power strip (also dropping the effective house voltage), etc.  If anything drops the house voltage enough, then this “chugging” can occur.  It’s due to the motor pulling more current on the push cycles of its rotation and the voltage for that momentarily higher demand falls and isn’t available when the motor is at peak demands.

It can also be caused by the filter being run for long periods on lower voltage outlets or if a filter has been dormant for a very long time. Long term operation at less than 120v can deform the capacitors and make them less efficient and cause this chugging. 

But that chugging will go away if you feed that FX6 with about 130vac vs 120vac normal house current.

Often, you’ll find the outlet with a chugging filter will have a voltage drop and read perhaps 105-115v from the drop caused by other loads or that circuit in your house.

However, a chugging filter can sometimes be “fixed” by operating it at a slightly higher voltage for 2-3 days. I’ve repaired two such chugging FX6 motors in this way.

The capacitors in the motor’s power supply tend to assume an internal shape over time from either running at a lower than optimal voltage or if left dormant for months or years. When this happens, the capacitors become less efficient at higher voltages and the overall power to the motor suffers a voltage loss. This contributes to the low voltage chugging problem, but often the capacitors may be ‘revived’ by a technique called “forming”.

A Variac is an autotransformer that can supply typically 130v up or to 150v and any value below this. By plugging the filter into a Variac and running it at 130v or as high as 140v, it “reforms” the capacitors in the motor’s power supply to perform at higher voltages making them perform more efficiently. Flow improves, noise drops, chugging stops and it uses significantly less house power.

I would guess that the Fluval was designed in the 240vac configuration and was converted for American house currents (120V). That would suggest the voltage regulators powering the motor are designed for 240/120 and many American households have less than 120v available on the wall and so that can destabilize the voltage regulation.

The room I have my system in has such a voltage drop. Only about 112v is available so I use a Variac to power my filters and the flow is strong, smooth, linear and consistent.

VARIAC

Since I have six FX6's, I use only one Variac for all 6 such that it made the addition of the Variac worthwhile. Otherwise, a $70 Variac per FX6 could make one think otherwise.

Still, in hindsight, I wonder if a decent pond canister would have been better. They are less than half the price of an FX6 with potentially enormous GPH’s. The submersible pump makes me nervous, but you can’t beat the $/GPH.

POND CANISTER

This is interesting. do you think it is worth buying one of those variac. I need to get a volt measurer. Next time i go downtairs (60 mintues from now); I'll plug the filter into the wall (it is in a power strip) and see if that helps. I have a watt meter somewhere - if i can find it i might give it a try (I think it measure both watt and volts). 

 

That pond filter looks ok but a little rough for an aquarium - i mean i'd have to find a nice spray bar and the biggest negative to putting the pump in the aquarium is it will suck up frys.