On the request of some people from another thread I recently made with pictures of my 900gal pond, here is how the diy filter is made. This filter can handle about 600 gallons nicely. It is not as good as maybe a 55g barrel filter setup but this gets the job done for a less bulky product. FYI This filter can be made into a bigger product but mine is just an example. Along with the filter is a sumberisble hooked up to a 280gph pump that then goes to a 8 watt lugana uv.

Materials: 1 Rubbermaid Container of your size (mine is 18 gal) with lid, 2 pieces of Pvc pipe half the size of your filter, 1 Rubber seal that can be found in the shower drain aisle and will need to be the size of the inlet that attaches to the drilled out pvc piece, 90 degree Pvc Elbow with one size having an inlet for the pvc adapter to screw in, 1 pvc screw in adapter, Pvc cap for one side of the pipe, 2 mesh bags ( can use more or none if you want, just ease to pull out of the filter is all), lava rock(about 1 and a half buckets for my size), Filter mats (I used some filter mats I had but also used cheap bio-degradable furnace matting..cheap$ and works well), inlet for pumps hose, rubber hosing to attach to pump, Pump( for this size a 600gph - 740gph, PVC Cement (comes in a small can in the plumbing aisle), silicone glue

Now with that all done here we go:

1. Drill holes in a piece of pvc pipe half or less the height of your filter, though leave about 3 inches on bottom untouched for it to leave room for settling and to allow the adapter to screw into the elbow, and 2 inches at the top for the cap to plug onto.
2. Drill a hole at the top of the container 2 inches from the top, this will be for the pump and hose inlet, use silicone to seal the inlet piece and help keep it a little more sturdy
3. Drill a hole at the middle of the bottom to the size of the screw in adapter that attaches to the elbow, this piece will be inside of the filter and have a seal between it and the plastic
4. Put the seal on the screw in adapter and push it through the hole and twist the elbow onto the screw in adapter once it is through, be sure to use pvc cement on all the seals of pipe with water running through
5. Attach the other foot long piece to the other side of the elbow and be sure to use pvc cement there to, this will lead the water back into the pond.
6. Place the filter in the proper location by the pond and it will probably have to be raised a little bit to keep the elbow and pipe from hitting the ground.
7. Place the lava rock in the mesh nets at the bottom
8. Place the fine mats on the lower section of the filter and the mats for catching larger debris on top.

Total cost for whole filter w/o pump was $39.... the pump was a cheapy from ebay for $25 FYI
Can be done for more or less if you have some of these products at home

Any other questions can be pmed or over this topic

Example of what it should semi look like without mats:


Before, you can see my tiny old diy box:


After:

Thanks so much for posting this. Your description is very clear, and has given me lots of ideas on how to build a filter for my pond. I see a trip to the DIY store in my near future!

Thanks... I tried to make it more of a visual then writing because thats how I kind of am so I hope it helps a lot of you new or experienced ponders out there. I have noticed a lot of people with plans for making a pond on this board recently to so maybe this will help and spark some more ideas from others minds to.

bump

Nice going there, Blondhairboi! That is a simple filter, yet effective. Have you thought of a way to backwash it when you want to clean it, of do you have to take everything out? Is the connection right where the pvc meets the bottom of the rubbermaid also sealed with the cement, or can you remove that?

I am just wondering, if you wanted to backwash the filter and remove all the debris from the first 3 inches of the bottom of the filter - if you could remove that part where the pvc meets the bottom of the filter, the suction would suck the debris right out of there.

In my case the seal was not that tight so I used cement but all I do is unplug the hose to top of filter after every thing is out. Then just lift it off the wood planks in the pic to go wash with water. I do know bigger rubbermaid containers have built in backwashers but it is still nice to take everything out once in awhile.

for my diy filter I used a 55 gallon pickle container (plastic). I have it hidden by rocks so you can't even see it. It has several layers of filtering throughout. The only downside to it is cleaning it. What a pain in the rear that is.

yea when it comes to filtration bigger is always better but this is for smaller ponds and to spark ideas for designs that others might like to incorpate with. This is similar to a barrel filter just minimized and is a mix of mech and bio.. I would really like to see one of these with bio-media completely ........ maybe an idea for me in near future.

My entire filter is bio material. It takes more effort to clean but is well worth it.