this idea may not be as extravagant as iturnrocks but it is working on my 125 gallon indoor pond and my water is perfect
The bucket filter
The 5 gallon bucket filter idea started because of the need of a larger filter for a pond. The only things needed for a bucket filter are a 5 gallon bucket with an airtight lid, a couple of fittings, a long length of hose the same size as the fittings, and a pump. To create the filter media, bacteria spawning balls and polyester pillow stuffing were used. The purpose of using the balls and polyester media is to create a soft water filter in the media and a biological filter in the ball area. The media will filter out all of the larger particles; provide an area for a small amount of bacteria to grow. The filtered material and humid environment will provide ideal circumstances for the bacteria to flourish. Later different media can be introduced to aid in other areas of ideal water chemistry; carbon, lime, ammo rocks, and a small ph controller (crushed shells).
The balls were placed in the lower level of the bucket along with the pump. A screen was placed atop of the lower level to separate the balls and the pump from the polyester material. A tube was run from the pump twice the height of the bucket to allow the lid to be removed. The pump and tube were placed in the middle of the bucket with a small hole cut in the wire screen. The polyester was then placed around the tube to fill the rest of the bucket. Make sure that there is not too much polyester in the bucket; it should on be packed but rather loose and free flowing. Also make sure that there is adequate room to upgrade to a bio/mechanical/chemical filter which will be explained later. `
The lid of the bucket should have 2 inlet tubes for every 1 outlet tube and 1 spare for the whole lid, these are created by using tube unions (preferably metal) along with washers, which are hot glued through the lid with the washers making an airtight seal. The holes for the unions should be the exact size that the unions can fit into without falling through. After all the unions are inserted and glued down from the top side it may be a good idea to silicone the whole thing, just to ensure the airtight seal (only around the fittings and glue not the o-ring on the bottom of the lid). On the bottom of the lid where the unions are protruding install a tube on each of the unions except for the spare one. The fitting that will be used for the pump needs to be connected; the others should have a tube that nearly reaches the middle of the bucket. The tubes should be tightened down using metal hose clamps.
The routing of the inlet an outlet lines for optimum performance should be routed so they are the minimum distance possible from the water surface. Also for ease of tank cleaning provisions should be made for an outlet to drain the tank from the pump line. The filter can also be used to vacuum the gravel by attaching a much larger to the end; the larger tube needs to be about 4 times the size of the gravel in the bottom and about 6-8 inches long.
Basically this filter is a bio mechanical filter. It mechanically filters out fish waste and uneaten food by means of a soft filter media i.e. polyester stuffing. And biologically filters out small waste and nitrites by means of billions of bacteria, the bacteria eat nitrites and create nitrates which are not nearly as harmful to fish. Later if necessary a chemical filter can be added, such as charcoal bags of ammo rock bags but these are not a necessity unless there is no time for weekly water changes (20-30%).
