fluval u-2 underwater filter Question

  1. MJDuti Well Known Member Member

    I just got one of these for a 10G planted tank. Was just taking it apart and checking everything out, which was real easy. Had a few questions though. First off, any thoughts/reviews on these? People seem to like them from what I've read and they have a lot going for them. I have 3 places to store filter media, adjustable flow options, an air filter (venturi valve).

    I plan on using the middle flow option (B) so it's gentle and won't blow away my stock or plants (has 105G/hour filter rate). Does the venturi valve only work when you are running the top flow option (A). As that's what it is connected to, however, maybe it can still take in air? I don't know. Does anyone even use the venturi, would it be beneficial?
    Now it comes with the central BioMax container with the pieces already in it, that's fine. The 2 containers on the side each hold a sponge/filter pad. Now I can't tell if one of them is the poly/carbon pad or not. I'm assuming they are both just the foam pad as I can't seem to see, or feel, any carbon in them. This leads me to my biggest question. Should I get the poly carbon cartridge? I hear that plants do better without carbon cause it drains the water of nutrients and such. However will my moderately planted tank help keep the water clean enough where I won't need carbon? I also heard it's really just to get medications out of the water, but when they sell it they claim it makes the water "clearer" and gets rid of any smells. If I don't go with the carbon, what are some other suggestions??? They don't seem to sell anything specific for it, however since it's in a grated plastic container I figure I could most likely put anything in there. What are your thoughts on say a mesh bag filled with something (like Nitra-zorb for example)? What would be some other useful filter media? Or should I just keep 2 foam pads and just replace 1 every month or so and stagger them? Anyone use filter floss? It appears the same as a pad, what is so different/beneficial about it?

    Guess I added a lot of questions in there. Thanks for any info!
     
  2. can haz catfishies? Member Member

    ok to answer a few questions, i run one of these on my 50L adf/celestrial danio tank
    the flow is good but i would expect a little less than it say's on the box in gph, but that said it is a silent filter, i have to look to see if mine is working as i never hear it,
    yes the venturi only works on the top outlet but if you use the flow director then you can get some nice surface movement oxygenate the water and reduce the current around the tank at the same time and not need the venturi, mine didnt have carbon but i wouldnt put any in to be honest, i have only ever used carbon if there was an additive in the water i wanted to remove,
    i wouldnt really add anything else to it, also i wouldnt replace the media every few weeks, mine has had the same media in it since i got it, just clean and rinse in old tank water then pop it back in, nitra zorb and other things like ammonia remover could be put in i guess but i dont seen the need if you keep on top of your water changes but really i would just have the sponges and then pack the middle with biomax, the more biomax you have the more surface area for bacteria.