So, I have a rain barrel I got for free from a neighbor, similar to something like this (http://www.homedepot.com/p/Unbrande...h-Green-Brass-Spigot-55100009004281/202402181). It's probably around 50-55 gallons, though I haven't measured it. Since it is "pretty" and not your ordinary storage drum, I was thinking it may be fun to try and integrate it into my pond upgrade, but I have no idea what to use it for. It's very sturdy and since it was free, i'm not afraid to experiment with drilling holes and adding piping, drains, etc. I thought maybe I would try to make it in to some sort of filter that feeds a waterfall and am looking for suggestions. I've been looking at DIY Sand and Gravel filters, but my water coming in would be coming from a submersible caged pump, likely in a skimmer, so the water will probably be kind of dirty -- not sure if an S&G will be appropriate. The new pond will be between 1500 and 2000 gallons (depends on how tired we get of digging), and my pump is a Laguna 2900 which will be split between my small bog (connected to a "middle pond" of about 450 gallons) and this barrel. Right now, all I have are 10 gold fish, so not a huge Bio Load, but I may dabble with 1 or 2 koi if the environment can support it (but that's a topic for a different thread...). Anywho, what do y'all think? I'd like to make something that is helpful for the water in some way and won't end up being a nightmare to maintain (although the occasional flush every week or two seems reasonable). Plus, it has to continue to be "pretty" ;-) Thoughts?