How You Build a pond filter.


Background

The filter that came with my pond kit was terrible; it had to be cleaned every couple of days and cleaning it required getting into the pond. My brother suggested that I build my own so I did some research on the web and I built my own. I designed the filter to have a 1 inch outlet on the bottom of the bucket for cleaning. The lid will have a hole in it and the tubing from the pump will connect to the half inch pipe that runs about 2 inches short of the bottom of the bucket. This vertical pipe connects to the center of a Tee. Each side of the Tee connects to 1/2 inch pipe that is a few inches long. At the end of each pipe is a 90 degree elbow. The 2 elbows face opposite directions to create a whirlpool action. The filter basically consists of 3 filter layers. The first lowest filter is a layer of lava rock. The second middle layer is a layer of scrub pads. Many filters of this type use bio balls or something similar for this filter layer. The third and highest layer is a layer of small pebbles. The main outlet is a 1 inch aeration tube that passes through the bucket call and connects to the tubing to run back to the pond. There is also another 1 inch connection aboce this one with a connection to tubing that run back to the pond. The purpose of this connections is to act as an overflow in case the filter does not work properly.


Instructions

  1. Select a bucket, PVC pipe, and connectors.

  2. Prepare the bucket.
    • Remove the handle. Drill a hole through the bucket for the cleanout port. This hole was a little less than an inch and was drilled close to the bottom. Make sure that you drill this hole high enough up so you do not disturb the bottom of the bucket. Select a drill bit or hole saw such that this hole is larger than the threads of your connector but less than the flange.

    • Drill a hole through the bucket a few inches from the top using the same drill bit used for the bottom cleanout port. This is the hole that will hold the aeration tube.

    • Drill a hole close to the top of the bucket for the overflow. I wanted this to be close enough to the top to serve as an overflow but low enough to not interfere with the lid. In order to drill a hole to meet this requirement, I had to remove part of the ridges of the bucket support at the top as shown in the following picture. I used a rotary tool and carefully removed the ridges. Next I drilled this hole using the same bit used for the bottom cleanout port.

  3. Prepare the 1/2 pipe assembly for the inlet.
    • Using the 1/2 inch pipe and connectors, connect a long piece of the pipe to the center of the tee using pvc glue. Connect a short piece of pipe to each side of the tee using pvc glue. Connect 90 degree elbows to each of these short pipe using pvc glue with each elbow pointing in opposite directions. The purpose of this arrangement is to cause a whirlpool action to move the water.

    • Cut 2 short pieces of pipe (about 2 inches long) and attach to the bottom of the 1/2 pipe arrangement. I drilled holes in these 2 pieces and passed a wire tie through the holes and around the 1/2 pipe arrangement. These 2 short pieces just serve as spacers to keep the elbows that control the water flow off of the bottom of the bucket. This arrangement will sit slightly off center so as not to interfere with the 1 inch aeration tube.
  4. Connect inlet and outlet ports.
    • Connect the 1 inch connector from the outside of the bucket with the threading passing through the hole and into the bucket. Screw the retainer ring onto the connector. Tighten this to make it water tight.

    • Glue a 2 inch long piece of 1 inch pipe to the cleanout port. Glue a 1 inch slip to thread connector to the other side of the 2 inch long piece of pipe. Wrap thread tape on the ends of the threading and screw on the 1 inch cap. I will probably change out this cap with a ball valve to make cleaning even easier but for now I avoided spending the couple of dollars for the valve.

  5. Assemble the filter layers.
    • I picked up some supplies at a dollar store. I bought 2 colanders for the rock and pebble sections. I also needed something to substitute for the bio balls and something to support that section. I picked up a frisbee for the support and a pack of kitchen scrub pads to serve as the bio balls. The colander was perfect; I did not need to drill holes to allow the water to pass. I cut off the handles on each of the colanders.

    • Drill a hole through each colander to allow the 1/2 inch pipe to pass through. Keep in mind that this pipe will be off center to allow for the aeration tube. Place the colander onto the 1/2 inch pipe such that the pipe passes through the hole you just drilled. Use a garden hose to thoroughly rinse off any loose particles or dyes from the lava rock. Place the lava rock into the colander.

    • Drill a hole in the frisbee for the 1/2 inch pipe. Again, keep in mind that this pipe will be off center. Drill a bunch of small holes through the frisbee to allow water to flow. The hole size should be large enough to allow significant water flow but small enough to prevent the pebbles from passing through. Place the frisbee over the 1/2 inch pipe assembly fitting the pipe through the hole you drilled in the frisbee. Layer the scrub pads over the entire area of the frisbee. I cut a slit in one of the pads and cut a hole so it can sit around the pipe.

    • Place the next colandar into the bucket. Thoroughly risne the pea pebbles and pour them into the colander.

  6. Complete the filter.
    • Cut a 9 inch length of the 1 inch pipe to serve as the aeration tube. Drill a bunch of small holes across the length of this pipe. Glue one side of this pipe to the 1 inch port. Glue a 1 inch cap to the other open end. Put this assembly into the bucket and pass the threaded portion of the 1 inch port through the bucket wall and attach the nut on the outside.

    • Drill a hole in the lid of the bucket to allow the 1/2 inch inlet pipe to pass. Snap the lid onto the bucket. I did not worry about making the hole in the lid a water tight connection; the water should never flow this high.
    • Connect the last remaining 1 inch port connection for the overflow. Assemble this through the bucket in the top most hold and secure with the retaining nut. Glue a 2 inch long piece of 1 inch pipe to the outside of the overlow port. Glue a slip to thread 1 inch connector in place.
  7. Connect the hoses
    • Connect the end of the hose to the hose barb connector at the inlet at the top of the bucket. This was a very tight fit; it took some effort to get the hose on the connector. Secure it with a hose clamp. Measure the length of hose that you need to reach the pump and cut it. I measured mine to be a little longer than really needed in case I decide to move the filter at a later date. Connect the cut end of the hose to the pump. I secured the hose to the pump with a wire tie; this step was probably unnecesary.
    • Connect another hose barb connector to the main outlet port. Connect one end of a hose to this connector and measure the hose for the length that you need. Put the cut end of the hose into the top of the fountain. I put a couple of rocks over this to secure it in place.
    • Connect another hose barb connector to the overflow port. Measure the length of hose needed to reach the fountain and cut it to length and secure it under a couple of rocks as well.

  8. Beautify the filter
    • I decided to hide my filter inside a large plastic flower pot that we had lying around.
    • Drill 3 holes in the flower pot; one for each of the hoses.
    • Place 2 layers of 2 bricks (4 total) in the flower pot and placed the filter on top.


Here are some pictures of the pond.


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