i've built a filter based on adam's filter but with a different combination of filter medium inside. it works nicely to prefilter my pump. i only have to clean out the pump monthly now instead of daily when the pump used to just sit on the bottom of the pond. when you burn or drill your holes in the container for the water to come in - don't put them on the bottom or low down on the sides of your container. this helps keep the silt that settles on the floor of your pond out. don't forget to see how your pump fits into the container before you drill your holes for the output of water & the electrical. it was an easy, inexpensive project & it made a nice difference in my pond.

Thanks gpacker. Do you mind telling me what kind of material it was that you used? I was wondering about putting holes in the bottom. Do you think 2" on the lower sides will be good enough?
Thanks for all your help.

I have a dense foam surround that came with a previous filter kit that the box only lasted 2 years. so i used this surround, then added those 3m foam scrubbies that you can buy 10 for a $1 at the $1 stores. usually like 3x5 size. or 4x6. if my water gets really dirty i add some quilt batting to the top for a quick fix but take that out after a few days - it gets very dirty - rinse and reuse when needed. the box i just picked one at the dollar store that fit my large 3900 gph pump. 2" off the bottom for the holes sounds fine or 2" worth of holes on the sides sounds good too. i just took a look at adams design - i see he doesn't have holes on the sides at all. i do. make sure you have plenty on top as he shows. if you look at his pictures 5b & 5d you see examples of the nylon scrub pad - i just use smaller ones. i don't use lava rock i think it plugs up to easily - same with the quilt batting. but try different options.

Hey there,
Adams mom, here,
the filter he built is still keeping his pond clear and clean,5 yrs later,He chose the differnt types of filter media based on what he thought he needed to clean his water up,keep in mind his small pond size as well,
I know that also part of his use of lava rock was for the biological growth of good bacteria as well as added weight to keep his filter system submerged,floating was a problem when he first experimented,,he has never had the lava rock plug up,, the quilt batting will, but if your filtering out small particles or green algae it works well but does need to be cleaned or changed more regularly,,
His does not have holes in the bottom, part of the reason for that is based on his pump pulling the water through the top and down through the filter media,,which is what mechanically clean the water,,
M
aka JwJ

Hey there Adams mom,:-)
I put me a filter together a few days ago and I did use the lava rocks. I didn't put any holes on the bottom but I did put a few on the sides. After I put it in the pond within 2 hours I could already tell it was working. After having it in the pond for three days I can see the bottom again.The only thing I didn't like is it takes up more room then I wanted. So I will be making a smaller one and will not put any holes on the sides. My pond is a smaill one also it's a 90gal.