Hey, sorry for the late post on this subject, but I just joined this forum.
I wanted to start out with a pond but before I did, I bought a 20 gallon plastic tub just so that I could see if I liked it before investing in a bigger pond.
I was all set to buy an expensive pond filter but a guy at the pet store recommended that I look on the web for a cheaper and just as efficient filter system that I could build myself.
I looked on line and found the Skippy filter so I made one following their instructions (and some advice from a bunch of other people) and started it on my little 20 gallon tub.
I know that my tub is tiny compared to a regular pond, but let me tell you this.....it freaking works wonders!
I have about 8 3" goldfish and about 40 feeder guppies in that little tub and at first I couldn't even see more than 3 inches below the surface. After only 1 1/2 weeks, my "pond" was COMPLETELY CLEAR...I kid you not.
I believe my water cleared up so fast because of it's small size.
I'm going to be switching to a 60 gallon pond soon, when I do, I'm gonna take before and after pictures and I'll also see how long I can run my filter without cleaning it. I've read on many sites that you have to clean the filter or else it gets really gunked up, but for an experiment, I'm going to let it go without ever cleaning it and see how long it can go before any major problems flair up. I know that the Skippy site recommends never cleaning, but other sites contradict this claim. Most people that post about this filter live in areas that have harsh winters so that they have to shut down the filter ever winter, so I've never read about anyone running it year round for more than a year. I live in Hawaii so I don't have to worry about the winter and I can run it year round, so since I've never seen a posting on how long it can go without ANY cleaning, I'll be the first guinea pig.
The only thing different than the skippy site that I did for my filter was I used nylon body sponges instead of scrub pads. I figured that the scrub pads they used were nylon and the regular scrub pads were so darn expensive, so I just used the body pads that I found at our 99 cent store... I'll try and take photo's of my set up later...peace out and hope this helps you make up your mind about the filter, I'm totally happy with my filter..