Hey gang !
This root clogging issue has been a major headache in the past (floods...)
I was never happy with the available RDWC designs, in particular those attempting to solve the problem by using bigger pipes.
How I solved it : Reversable flow design !
My setup has two constant level tubs ; You can do the same with just one tub and from here on I'll describe it as if there was only one.
The tub has:
-A drain hose at the bottom,
-An overflow drain on the top.
-A Feed line (which you can see going over the tub, in the back)
Water level is set using a section that goes back up on the drain line, set right Under the level of the overflow.
The overfllow has a short crystal section: If roots clog the main drain line, water level will rise to the overflow level and I will be able to spot it in the crystal section.
This is when I reverse the flow for a couple hours : Using the shutoff vavles, I can make it so that the drain become the feed(and overflow become the drain).
This will push back all roots into the tub, and then I switch the valves back to normal.
Hope this helps !
I might create a thread to explain the design better if you guys ask for it