Aqua-Tech Ultra Quiet Power Filter for 10-20 Gallons

I purchased the typical 5 gallon set-up with comes with everything except the fish, water, gravel and seaweed embellishments. I have two 3" goldfish in this tank and they quickly overwhelmed the filter with their by-products (dung). The tank started getting cloudy in 4-5 days and steadily got worse. I did a few partial water changes but the cloudiness persistently came back. The goldfish started to show signs classic signs of Ammonia Burn (their fins and gills started turning black). So I upgraded to this filter thinking that it would solve the cloudiness/Ammonia problem but it did not. As it turned out, I noticed that dung was getting trapped in the seaweed, gravel and plastic log I had in the tank so I removed them all and did a full change of water. Since then, the cloudiness has not reappeared, the black burns on the fins and gills has disappeared because the filter sucks up 100% of the dung. I still think this pump is part of the cure mainly because it really stirs up the aquarium and gives the fish a work out if the swim into the stream. It was a great upgrade! PS: The fish could care less about the gravel, seaweed, all these pigeons of the sea care about is their next feeding...