When you think of your pond - think circulation and filtration. As a rule usually a pond under 1000 gallons needs to be turned over every hour. A pond over 1000 gallons turned over once at least every two hours. Consider your pump GPH- and the head (resistance) that your pump is working against. For example a 3000 GPH pump may only pump 1800 GPH as it pushes water up a 3 ft waterfall and thru 20 feet of pump. So if your sytems is adaquately circulating, then go to filtration.

Most people pump all their water thru their filter system at a high rate (GPH). Most filters don't work well this way. The larger debris is forced thru the filter material, ground up in to smaller particles, blows past the filter mats and back in to your pond. Are you using a Tetra clear choice filter or a pressurized system or both? If you are using the pressurized sytem then I would recommend a good prefilter before it to catch the larger debris.

For the Tetra clear choice then I recommend that you split your water input to that filter, such as using a T fitting then running part to your filter and the rest to your waterfall. The Tetra clear choice is an excellent trickle tower if used in that way providing a relatively cheap, effective biofilter.

Hope this helps. Happy ponding.