Could be user flaws, the OP stated that it was overtightened. I dont know exactly how they go together, but it wouldnt be that hard to figure out how many turns is the right number, and just always turn it that number of turns.
I guess I am just use to things that cost money to fix, sometimes often. Aquaclear hob filters are known to become loud at some point and you have to lube the rotor, or just totally replace it. I knew that before buying my 30 and ended up running into the problem, but a quick diy fix and the only noise I hear is the water going back into the tank. Even the most expensive things can still have design flaws. Nobody is perfect, and most products normally have one flaw, be it major or minor. Many of them people would never know about unless they opened them up.
Something such as a filter is prone to failure at some point in its life, may be something simple like a clamp breaking, or a little more troublesome of the motor stopping.
Well, it seems that I have opened a can of worms that I didn't mean to, lol. In my defense, they were already cracked when I bought the filter used, I thought it was a little odd. But I gotta put my word in.
I really like my fx5. Other than it obviously leaking, I haven't had any other issues with it.