The snow is finally melting on the East Coast, so I'm now starting to think about building a 110-gallon patio container pond. I've located a heavy-duty plastic stock tank for $70 and plan to construct a modern looking cedar wood surround using some leftover materials from another project. My question is about filtration. I have always had fish -- I currently have a 75 gallon salt and 30 gallon goldfish tank -- and I have a bunch of filters lying around that are not being used. I'd like to repurpose one for the pond, but having never had a pond before, I'm not sure if it would be adequate. The one I'd like to repurpose is an Eheim Professional 3, which is rated for aquariums up to 160 gallons, and has a maximum flow rate of 330 gph. This filter works fine as a filter, but it has been a thorn in my side since I got it. It was expensive and has leaked almost from the start. It is a common problem, but Eheim is ignoring customer complaints (including mine). So, the filter has been just sitting around unused. The good news is that my husband has managed to fix the leak using a YouTube video by someone in Germany who had the same problem. However, I don't trust the filter inside on my hardwood floors. However, outside would be fine. Can I safely use this to provide adequate filtration for a 110-gallon patio container pond? I don't want to overstock with fish. I'm thinking a total of 5 fancy goldfish would be my goal. Thoughts?