Fluval U1 Filter

[JoshuaA]

Hey there!

I'm trying to get to the bottom of this, I have currently a stingray 15 filter and want to replace it I have an Aquaball filter which is too noisy and a cheap Aqua Flow 1 filter which I know nothing about so don't want to use it as I don't knows its capabilities.

The Stingray is plagued with problems and it seems that if I just look at the filter something goes wrong with it. I've had to take it apart and mess around with the motor/impeller about 5 times in the last week as the case doesn't seal properly from brand new and allows sand/plant and other debris to enter the filter by bypassing the sponges.

I currently have modified the stingray filter to make up for the fact I have removed the Carbon/Zeolite cartridges. The modification is A small packet of Ceramic nodes in the main compartment, then 2 small sponges either side of that compartment and then finally a small fine sponge directly over the filter impeller to prevent the ceramic media being sucked in.

So as I bought my girlfriend a Fluval U2 filter to replace this Stingray 15 on her tank and all has gone well with that filter, I was looking at buying a Fluval U1 filter for my tank (40L).

However upon looking through this from what I have initially found appears that the Fluval U range is "3 Stage filtration" bar the U1. The U2/U3/U4 all using 3 stage filtration however the U1 appears to just use a sponge.

I like the ceramic media and as I have found it to be very successful find that the Fluval U range is very attractive because of this property. However now that I've just noticed the Fluval U1 is only a sponge it feels like it loses ALL of its great points about it.

However I have found numerous websites still claiming that the Fluval U1 is a 3 stage filtration filter and numerous sites claiming it is a sponge filter only.

The problem this presents is the fact that I have partially cycled my Stingray 15 filter. It is processing 4ppm of Ammonia pretty fast now and slowly processing some Nitrites. I would like to be able to preserve this by transferring some of the ceramic and sponge although if the Fluval U1 only accepts sponge I'm a bit bummed.

The Stingray 15 output is far too powerful for my 40L tank and takes up far too much space, I lose a good 15/20% of my tank due to the fact it makes a huge disturbance in the water flow and takes up a lot of space.

If this is true about the Fluval U1 only being a sponge filter can anyone direct me towards a small filter which will have some sort of sponge + Ceramic? I've been very disappointed to find out that the fluval U1 is a sponge only.

I however would be willing to "Modify" the Fluval U1 sponge if it meant I could put a layer of Ceramic media down the centre of the sponge by cutting it in half. However Has anyone got any experience in using it?

 

[JoshuaA]

Ah so this is where it goes, I found a post asking some what of a similar question in that section of the forum which wasn't moved by a moderator who replied so I believed it was suitable there.

 

[JoshuaA]

So I bought a Fluval U1... Started cycling and!

The sponge is useless, it keeps blocking up on the intake and the output of the filter drops from full power to a level in which the venturi valve doesn't even receive enough of a vacuum to blow bubbles.

I have had to flip the sponge over because of how blocked it got and it restored to full power but over the period of 5 days it blocked up again so now I have a sponge full of bacteria but useless for cycling a tank because of it... What do I do?

It works great up to the point the bottom of it starts to blog up, at that point its pretty much just a powerhead as it does nothing but push water around bypassing the sponge!

Furthermore the filter intake is nothing compared to the Fluval U2 or higher which is extremely disappointing. This Fluval U1 filter only uses the bottom 20% of its intake due to the filters power where as the Fluval U2 and onwards use the entire intake.

Overall I am somewhat disappointed in this filter, being less powerful and reliable than I had anticipated. The look of it is quite nice from the stingray filter I previously had, although it doesn't help when my cycle almost stops due to the filter inability to maintain output.

Has anyone got a fix for this? Squeezing the sponge etc hasn't really helped plus it won't beneficial seeing as the sponge/filter is still cycling.

 

[saltwaterfanatic]

Return the fluval u1 and buy an aquaclear 20

 

[OldMan47]

It sounds like the U1 may be undersized for your present tank conditions. Although I would hesitate to recommend a specific replacement, you are experiencing a case of getting too much suspended solids for the size filter you are using. Cures include both removing the loose material with a good gravel vac or frequent cleanings. I use much larger filter housings in my tanks than are recommended although I seldom worry at all about flow rates. Results are simple to state, my tanks sometimes require me to clean them manually but never suffer from a lack of biological capacity.

 

[yabadaba]

I had exactly the same issues with a Fluval U1 and replaced it with an Eheim Aquaball 60 - you can transfer most/all of the media over so that what beneficial bacteria you have cultivated so far won't be lost. I notice you say you've tried an Aquaball and it's too noisy, which seems odd to me, as I have 4 Aquaballs now and all are quiet - about the same as their Fluval U series equivalents. I'm thinking maybe you were running yours with that silly bit of tubing (venturi) attached to the top of the outlet nozzle? I quickly removed all of those as they tended to create quite a bit of unwanted noise even when supposedly turned off!

 

[JoshuaA]

The problem is I'm currently cycling so there is like no debris at all in the water! It really does seem to be purely bacteria clogging the sponge up at the end.

I have a Eheim Aquaball but it is sooo noisey I'd rather not bother with it and that was without the venturi valve. It's a very silly design that one I don't really like it at all the venturi valve on the aquaball that is, though I do initially like the aquaball as it does seem to be a great design, the noise of mine puts me off and I can't be bothered forking out the cash to try and solve it. I do trust you in that yours is silent, I imagine there must be something wrong but after breaking it down multiple times I can't solve it.

I decided to get the Fluval U1 as I only paid £12 for brand new where as buying the additional filter cartridge for the aquaball to make it an aquaball 60 would be almost exactly the same price.

 

[SilverBlack]

I had exactly the same issues with a Fluval U1 and replaced it with an Eheim Aquaball 60 - you can transfer most/all of the media over so that what beneficial bacteria you have cultivated so far won't be lost. I notice you say you've tried an Aquaball and it's too noisy, which seems odd to me, as I have 4 Aquaballs now and all are quiet - about the same as their Fluval U series equivalents. I'm thinking maybe you were running yours with that silly bit of tubing (venturi) attached to the top of the outlet nozzle? I quickly removed all of those as they tended to create quite a bit of unwanted noise even when supposedly turned off!

Had the same thing with a U1 too not so much the sponge but the impeller needed constant cleaning.
The flow dropped to a trickle after a week and its a nightmare to dis-assemble to get at the impeller.
Ive just replaced it with an EHEIM 2008 PICK UP filter.

 

[waterdrop]

Interesting thread and I'll be interested if more results get posted. The problem of finding high-quality small filters has seemed to hang around, at least from my reading.

About the smallest filter I think I've experienced (excluding simple box filters of old) is the Aquaclear Mini (now called the Aquaclear 20) I'm currently running on our quarantine tank. I find 3 (not always present but potenially there) noise problems with this filter: first, the impeller and shaft are not as high quality as you'd find in an expensive filter and can get noisy over the years; second, its an HOB, so there's the built-in waterfall noise that you can only escape right after water change time; thirdly, there's the little plastic top cover, which can hum and which of course you could choose not to use or to modify I suppose. Of course, the simple rectangular media box gives maximum flexibility, which is what makes all these ACs be contenders in the first place.

One natural advantage of internals is the potential for very quiet operation due to complete submersion - its a shame when the designers don't take full advantage of that.

Over time I seem to recall occasionally running across little tall vertical glass box "sit-besides" and I've seen a few very small external cannister systems, but unfortunately I've not captured any info on these and saved it (always feel the need to get better at that!) Perhaps others will come along that remember some of these other types. Perhaps there are some companies out there making fancy nano-planted-tank equipment who might have some nice stuff, albeit expensive.

I do feel that filter designers run up against some difficulties when sticking to very small filter volumes. The whole concept of a bed of media material with water and debris slowly moving through it begins to meet with some difficulties as the overall bed size gets closer to the individual media particle size. The ability to increase dwell time decreases, I would think. Mostly I think budget considerations are an even bigger factor.

Anyway, I wish you the best of luck muttling towards the best solution Josh, if anybody can get there, its you!

WD