Larger Filter Or Add Another Small Filter

You could do either but check that a u3 would fit vertically once in position.

If I were you, I'd add a second filter such as the u1 in addition to the u2, rather than replace the u2 with a u3 - always handy to have two filters running in the event of a filter failure (and easy to take the small one out of the tank in an emergency for use in a quarantine/hospital tank if required).

Ah yes the forum syndrome.
Yes do it, no don't do it....

So i could add a foam filter that would not increase water movement but still be available to move to another tank if needed and I could put more filter media in the existing filter as there is lots of room to do that.

I already have an air pump but never liked the noise from it, I could just turn it off when i don't want to hear it.

Thanks.

Ah yes the forum syndrome.
Yes do it, no don't do it....

There is nothing here in the comments that is contradictory, so essentially it's over to you to work out what to do on the basis of the info we've supplied.

It seems that, on the basis of the collective advice:
*there would be little/no point in swapping/upgrading the u2 to a u3;
*whether you want to have an additional u1 depends on whether or not it is of interest to you to have a 'back-up filter' in the event that the u2 fails or to have ready to hand in the event you need to set up a hospital/quarantine tank in an emergency BUT it will add extra current and so whether or not to have it depends on whether you have fish which are sedate or those which require this. [Looking at your list, I see you have red cherry and japonica shrimp, julii cories, cardinals and harlequins - I would say that none of these require extra flow.]

So i could add a foam filter that would not increase water movement but still be available to move to another tank if needed

A foam filter would increase water movement/flow but, yes, it would still be available to move to another tank if needed. There would be no harm in buying a u1 for a hospital/quarantine tank - if you want to see how the current inhabitants get on with it as a second filter, you could try that, but if they get buffeted about too much, then probably best to keep it out of use as a spare for the hospital/quarantine tank rather than kept in use in the main tank.

Hope that attempt to clarify/summarise is helpful (and hasn't confused further!).

So i could add a foam filter that would not increase water movement but still be available to move to another tank if needed and I could put more filter media in the existing filter as there is lots of room to do that.

Yes this is another option you could do

The first thing to do is make sure all the bits are there. I have Eheim filters and with those the impeller is seated on a shaft with a rubber 'thing' at each end of the shaft. If the U's are the same, make sure there both rubber 'things' are in place.

Air can also get trapped in the impeller well - keeping the filter fully submerged, tilt it from side to side while running.


If those fail, see the shop.




I don't think anyone took offence - I didn't. Everyone has different ways of doing things