When looking stuff up to answer a question someone had on this board, I found this review of one of the filters
"I purchased the filter for my 10 gallon tank. It only has 7 fish, not overcrowded. Even though the tank was cycled, the water remains cloudy. I resetted my tank ( difficult and painstaking ) only to find i=out that again, week 2 produced very cloudy water.
I noticed that the filter doesnt work well at all. The water intake takes in too much water that it overflows all through the sides of the chambers and over the filter itself. THe sediments do not get filtered. They simply go back into the tank. Basically, it stirs up everything and put iut back.
I am on my way to purchase a Bio-Wheel

"
There are so many things wrong with this review. I'm sure you've all noticed the first one. Unless this guy's got seven one inch fish, his tank is likely very overcrowded. Also, I've noticed, in my attempts to run a tank with no power filter (failed experiment, but I learned things), that a filter does very little to clarify water. Its greatest effect is to remove ammonia and things that produce ammonia from the water. Hmmm... Restarted tank and in two weeks the water was cloudy. Bacterial bloom, anybody?
The only thing of merit in his post is the comment about the overflow, but with the rest of the guy's post, I wonder if he's changed the mechanical filter at all, or if he put the filter together properly.
It's not the lack of information that bothers me, though. It's the perfect willingness to blame what sounds like an extended bacterial bloom on the filter, rather than doing some research, or finding a forum like this and ask around (like I did a few months ago

)