After building my 1,500 gallon goldfish pond I started checking into filters. My brother bought a nice one from a local company for eight hundred dollars and it works great for his pond but that’s more money than I care to spend. Since I was able to build my own pond I thought I might as well make my own filter.
I checked the local newspaper and found several people selling used fifty five gallon barrels. The one I bought used to hold wine so it had a lid with a steel ring around it that sealed up very tightly when I pulled the handle. After a good cleaning it looked like a new one and only cost me twenty dollars. I wouldn’t recommend purchasing the barrels unless you know what they had in them. You certainly wouldn’t want one that had chemicals or hazardous materials of any type in them. I would stick with drums that once contained soap, wine, beer or any materials that wouldn’t be harmful to fish in case they still have slight amounts of residue in them.
I found almost all the necessary fittings I would need for the filter at the local hardware store. I purchased four eight foot lengths of inch and a half pvc pipe, a tube of silicone, a can of pvc glue, four bags of lava rock, a section of egg crate measuring two feet by four feet, several 90 degree elbows and a submersible sump pump. While I was at the hardware store I picked up a small inch and a half diameter saw you attach to your drill to cut holes in a door for a dead bolt or door lock. I bought a shut off valve and a check valve at a swimming pool company.
The last item I needed was a plastic milk crate measuring about 12 inches by 12 inches which I got from the milk man at our local grocery store.
Use your drill and the door saw to cut two holes on opposite sides of the barrel about two inches from the bottom. The holes will be an inch and a half in diameter. Cut another hole about two inches from the top of the barrel.
Place the sump pump on the floor of the pond and attach enough pvc pipe to bring the line to one of the holes in the bottom of your barrel. Install your check valve just before it enters the barrel so it will prevent sludge from back flushing into the pond when you clean it or the power goes out in a storm. Push the pipe into the hole far enough to glue one of the elbows to the end of it. Aim the elbow down and put silicone around both sides. The lip on the elbow will keep the pipe from coming out of the hole when you turn the pump on and the silicone will keep it from leaking.
Place the milk crate upside down on the bottom of the barrel. Take the barrel lid and lay it on top of the egg crate and trace around it with a magic marker. There should be enough egg crate to trace out two of these circles. Cut the circles with a jig saw or break them off with needle nose pliers. Place both of the egg crate circles on top of the milk crate. Rinse off the lava rock and dump all of it on top of the egg crate.
The rock should be a few inches from the top of the barrel and below the hole you cut earlier. You’ll use the top hole to return the clean water back to the pond. Just push a pipe through the hole like you did on the bottom one and run it back to the pond.
The other hole on the bottom is for the cleaning the filter. Glue a piece of pipe about three inches long to the shut off valve. Push the other end through the bottom hole and attach an elbow. Put silicone around the hole on both sides of the barrel wall.
Most of the nasty stuff sucked up by the pump will be trapped below the lava rock. Simply shut off the pump and open the shut off valve. You can let the water drain on the ground or use it to water your vegetable garden like I do.
Total cost of this poor mans filter was two hundred dollars and it keeps my pond nearly as clear as my brothers eight hundred dollar unit.
The one big disadvantage to my filter is its appearance. It’s not the most attractive thing to have sitting next to your pond so I put mine in a shed a few feet away and ran the pipes under ground so the entire filter system would be out of view
