Use a large tub or bin you can get at Menards or Farm Supply. Remove the plug at the bottom and replace it w/ a small (6-10") piece of PVC. Put a 90 on that pointing up, another piece of a PVC 15-24". The height of that piece will determine the height of the water level in the tub. Another 90 pointing outward away from the tub. again a small piece of PVC. That tub placed by the edge of the pond, either buried in the soil or level on the soil, will act as the filter. Put the pump (as big as you can afford) in the pond with it plumbed into the bin. Fill the bin w/ water lettuce and hyacinths and rinse the fiberious roots regularly and you will have clear water. If I can find some pictures of my old pond w/that system I will post them.