in my quest for over complicating things, i was talking with a friend whos putting together a rdwc system, and we were discussing how with the standard rdwc plumbing that you often are left with quite abit of dead space when you try to drain the system.
so we got to drawing things on the dry erase board and we got to thinking - why dont we plumb it from the bottom?
i mean, hes thinking about using uniseals and ive used them in the past with great success, and using the bottom of the buckets you would have a nice flat surface for the seal and pipe to push against, instead of a curved surface like the side of the bucket. thinking using 1 1/2 or 2 inch pipe. put the buckets on stands and plumb this like this crude 6 yr old drawing.
MAy be complicated but I like the idea. Take a look at the following (some photos):
Those buckets (from slucket buckets) have the inlet port at the bottom. During a draining operation, the inlet ports and the return ports serve as the drains. The buckets have a slope and they do completely drain dry (no lip around port).
As long as some time is spent ensuring a small grade on the feed and return lines, you could remove nearly all of the liquid from the system using the same re-circulation pump (and/or by gravity).
The concern I have with those buckets is that, by default, the bottom-side ports are slip fit (unlike proper bulkheads). And, the plastic for these is HDPE. So, being concerned with a potential leak, you’d have to think about ways to ensure the fittings remain tight. HDPE is not conducive to the typical adhesive. You’d need special adhesive intended to bond to HDPE (3M has some). I haven’t had a leak problem to date on that system, crossing fingers.
From what I’ve seen on the tube what you’re after seems similar to a gravity bucket system where your pots are staggered in a diagonal 45 degree angle the tube goes into the top of each bucket and runs down to then flood onto the next bucket from the bottom of that bucket connected to the top of another bucket and then so on and so fourth until you get down to your pump which would be pumping it all back to top.
Think it’s called a waterfall bucket system or something
