Monday, October 15, 2012

Built a better pond filter yesterday

Update 3/29/14:  I figured I would add some more details to this post.  It is amazing how many people are looking at my filter!  It cost me about $20 (not including pump) and works perfectly. Granted, I did have most of the items laying around, but you might too!  Another advantage is that the PVC is not cemented together. I just cleaned the filter out after a year, but it could have gone much longer without clogging. Cleaning took 10 minutes.  The water is crystal clear!
1 bucket (minimum 5-gallon, but you can go bigger if you want)
About 4 feet of 1/2" PVC (again, for large ponds/pumps, go with 3/4 or 1" pipe)
2 PVC elbows non-threaded
1 PVC elbow female threaded on one end
1 PVC Tee non-threaded
1 connector male thread/hose bib to match your hose
teflon tape for taping threads
1 PVC straight connector (for outlet tube)
length of hose (I used old garden hose 5/8"id)
1 hose clamp
Stiff screen or mesh (I used 1/2" mesh)
Thin window screen (optional, depending on media used)
Bio-filter balls, lava rock, or both (I had and used both)
Silicone or gutter caulk for outlet hole

Take a 5 gallon bucket, some 1/2 inch PVC and fittings and assembled as you see below.

Cut a hole in the side about 4" from the top and inserted the outlet tube.  The straight connector (under the screen cover in the pic) helps form the seal.

Using gutter caulk or silicone, seal the outlet tube well.

The idea is to make the water cyclone in the bottom.  It keeps the inlet clean as it pushes the water up through the filter.  Use a mesh that is strong enough to hold your filtering media up off the bottom of the bucket.

I added a few bio bags from the fish store. I don't know if they help, but I'm sure they can't hurt. One of them I pulled directly out of my fish tank in my house.  The thought is that some of the beneficial bacteria that keeps the little fish tank clean will help the pond.

Fill with bio-media.

Attach hose and clamp.  Turn it on and check for leaks.  I don't care as much about how it looks as I do about safety and water retention, so I just hang the edge of the filter over the edge of the pond.  That way if the outlet tube ever leaks it will just drip back into the pond.  

Notice this filter has no lid and is not pressurized.  It does not need to be.  The filter has never clogged or overflowed.  It has worked flawlessly. 

The only negative about this filter is that it's an eyesore!
I thought that if I wanted to improve the look I could put a decorative barrel over the entire filter, but that's for another day!

Feel free to comment with questions or design ideas...


  1. at last a clearly explained diy filter!! Thank you, this is great, all listed perfectly and great pics :)

  2. Thanks for this very useful filter..nice n clear instructive..easy to build...

  3. A wonderful filter. I might add an outlet tap just off the floor of the bucket for easier cleaning. With the pump running and an additional dousing down of the stones, all the accumulated matter in the bucket would get flushed out of the bottom valve.

  4. I just made this for $22 in under 10 minutes! I didn't include the bio bags in the cost as we had these from years ago. Thanks for posting this! Our new ducks are going to love it!

  5. There are some great spray paints for plastic if you wanted to make the bucket look nicer or add plants or rock around it. Thanks so much for sharing this! I'm off to Lowes with your list! THANK YOU!!!

  6. So the hose attached to the pump and than it pumps the water through the hose through the bucket and than back in the pond?

  7. Paint the bucket black. Sink it half way in the pond. (as long as the outlet is above the water line). Then plant some marginals on top and that will further the filtering.

  8. You could always find a flowerpot to build it in (one without the hole in the bottom :) ). Find a shallow bucket to set on top of the lava rocks and plant a sedum garden...The planrs would be removable in that top for cleaning.