I'm with you, Chris ... don't want to spend money where I don't need to ... I'd rather *divert* it to the stuff I really need/want. However, I don't know if letting the rain barrel just overflow is a good idea; maybe it depends on where one lives. We've extended our downspouts out a bit from the house to avoid water problems. It isn't uncommon here to get heavy downpours on frozen earth (sometimes with a nice layer of snow), so if the water is discharged close to the house, naturally it goes where the earth is most pourous, i.e., right next to the foundation. (Glad to see I'm not the only one with household projects hanging ... seems that houses, like gardens, are never finished.)

The current (March 2010) issue of The Family Handyman magazine has a nice piece on making a water storage system from trash cans and common PVC fitings. Good stuff that you may be able to adapt. Look for it on the newsstands or at the library. Craigslist is a great resource but sometimes you need to be patient to find just what you are looking for. The holy grail for rain barrels are known as pickle or olive barrels. The entire top screws off so there basicly like 55 gallon mason jars. Being able to remove the top makes plumbing them up very easy. As far as using metal, many drums are epoxy lined and will resist rusting very well.

Actually, the more I think about it, it definitely is a siphoning effect. The water level always drops to around 1/3 when this happens, and I have 3 rain barrels all connected together. Too much of a coincidence for it to ALWAYS drop to 1/3, with me having 3 rain barrels. I have my overflow pipe coming up from the bottom of the middle barrel in the configuration, with a hose connected at the bottom and running into the yard. Ideally, as the water level rises, it hits the upper level of that pipe (inside the barrel) and starts draining out the overflow right down the center of the barrel and into the yard. HOWEVER, my center barrel also happens to be a closed system. Other than the overflow pipe, there is no outlet to exchange air for the water coming into the barrel (the outside barrels both are vented - one with downspout entry, the other with a nail-sized hole on the top). So, when that middle barrel completely fills up (like it does in a downpour), it then completely fills up the overflow pipe and siphoning effect occurs. It then siphons ALL the water out of the outside 2 barrels, until enough water is siphoned out so that the level drops to the top of the overflow pipe in the middle barrel. It then slowly levels out the water from that 1 full barrel to all 3 barrels. That's why it's always roughly 1/3 full after this phenomenon occurs. To fix this, I need to get some air exchange happening in that middle barrel. To do so, I have to eliminate the "closed system" aspect of my middle barrel. I can do that by simply putting a nail-sized hole in the top like I did in the other. I think I'll try that first. Oh, and the reason I didn't see this happen when I tested this before, is that I didn't let the water completely fill high enough and long enough for the siphoning effect to start. It would have been a period of time AFTER the barrels all appeared full. I obviously didn't wait long enough. I think that makes sense to me. Make sense to anybody else?

I live in Columbus and a local farm store sells empty plastic barrels about the same size as the ones in the catalogs for about 10 bucks. The only problem is they are used and Im not sure what was originally in them.