internal filter Internal/underwater filter- keeps clogging

[Kat_Rigel]

So far, I am NOT a fan of this internal filter (Fluval U1.) But it was free, and that's a pretty good price. I want to use it more like a powerhead, just to add some extra flow in a certain area of the tank. I have it "hot-rodded" with sponge and a handful of biomedia, but it can't even go 1 week without becoming so clogged that the flow stops almost entirely; tbh, I'm surprised the motor hasn't burnt out. I don't think my tank is really that dirty; maybe the sponge is too fine? (But again, the sponge was free in my "box of random aquarium stuff.") I might also try placing a thin layer of sponge along the sides instead of piling it in like a HOB; the flow is designed to come in from the side, so maybe that will fix it.

To use this for flow only, I think I will still need a sponge to prevent debris and obnoxious tiny snails from getting into the impeller. Aside from making the sponge thinner, is there anything else I can do to alleviate the problem? Do you think I'd be better off with polyester floss?

I have the same issue with my HOB's intake sponge, just gets clogged up so easily. I might be overcomplicating this; I think I just needed to type it out and bounce some ideas off of people. I'm also curious if anyone has had similar issues with internal filters? I have rarely heard anyone say anything good about them.

 

Imagine a bag of biomedia on the top here:

 

[Sykes]

Yup, I think you answered your own question. Sponge on sides only (i.e. covering intake) and using a coarser sponge would be my only 2 ideas. I've never used that type of filter, but I could see how it wouldn't take much to clog something where water has to come in from the side and then turn mid-sponge to go out through the top. Your sponge doesn't look particularly fine though, so maybe test just changing the positioning first?

I would not use floss in that. Since there's not a separate reservoir for the filter media vs the impeller, I'd be concerned about the floss wrapping around the impeller and jamming it.

On a related note, sometimes free still isn't worth it. Sponge filters are cheap, and you'll likely want the air anyway. Plus if that thing pulls more power to try to compensate for being clogged, then you're paying for it in your electric bill. 

[Kat_Rigel]

9 hours ago, Sykes said:

Yup, I think you answered your own question. Sponge on sides only (i.e. covering intake) and using a coarser sponge would be my only 2 ideas. I've never used that type of filter, but I could see how it wouldn't take much to clog something where water has to come in from the side and then turn mid-sponge to go out through the top. Your sponge doesn't look particularly fine though, so maybe test just changing the positioning first?

I would not use floss in that. Since there's not a separate reservoir for the filter media vs the impeller, I'd be concerned about the floss wrapping around the impeller and jamming it.

On a related note, sometimes free still isn't worth it. Sponge filters are cheap, and you'll likely want the air anyway. Plus if that thing pulls more power to try to compensate for being clogged, then you're paying for it in your electric bill. 

Ah, good point. I didn't think about electric bill. Thanks! 

[Jeremy B]

maybe a thin piece of sponge at the bottom of the filter and bioballs on top?