I've got a bit of a dilemma :/ I got a fluval filter free with a magazine subscription, but the one that has been sent to me is a U3. The U3 is for 90-150l. My tank is a 48l.
I have read that you can't over filter a tank, and that it'd be better to go for the next one up. The trouble is that it is pretty much the same height as my tank. It will fit into the tank, but will need to be sat on the gravel to stay under water. That shouldn't be a problem because it takes water in from the side, not the bottom.
So my question is basically shall I use the U3, or shall I try and exchange it for a U2, which is for a tank my size :/ please give me as much advice as you can!
Thanks in advance for your help