sumps ---????????have you made your own ?

[RTR]

I am ultraconservative. I use redundant overflows - all over-the-back - to be sure the upper tank does not overflow. The input line to the upper tank I usually release at the water level, so that it sucks air immediately in a power-off situation. If I must release the upper tank input below the waterline, I drill a hole just below the waterline and brush it clean every week without fail to be sure it never clogs. That will suck air if the power fails and the input starts back-siphoning. Always have back-up. Never rely on power-on to hold water levels safely.

[Myaj]

The overflow box I have had two overflow tubes, one was backup incase the other got plugged. Part of it is also getting everything figured out just right so that if your tubes both got blocked somehow (or lost the siphon) that the return pump will run dry long before the top tank overflows.. Sure you get a burned out pump, but that's a lot easier to fix than a flooded room, at least if its a living area.

Drilled is a heck of a lot "safer" as far as keeping the flow going, the overflow boxes depend on a siphon.. but they do a good job and its not recommended to drill an older tank (glass gets brittle and prone to breaking), so generally drilled is only recommended if you are buying the tank new and having it drilled, or if you are very brave

PP - "car boot" = "trunk" in American English, hehe

[autophotos]

ah - so do you have trunk sales??