Durso/Plumbing sizes

[bjocque]

hey yawl, long time lurker (possibly) first time poster, am currently getting gear together to overhaul a hollywood farms rimu cabinet and 3 foot (170-ish litre) aquarium and wanted to know reccommended sizes (diameter) piping to use (marley??)

very much like the idea of using the skimmerless overflow system into a weir (lee's specimen container - cheers michael) then out through a durso standpipe set up, reducing down in diameter and then into the sump, return path through a eheim 1250 and back to main tank through a fluval output nozzel (have been toying with the idea of a spring loaded non return valve in here to prevent back siphon in case of power issues) - will plumb in on return line a return to the sump and a "upgrade line?" in case i want to add in anything later, hmmmmmmmmmm guess i should do a branch for water changes too, getting bigger than ben hur)

32mm seemed a little large for the durso pipe to me, i was wondering about a 25mm pipe reducing down to a 20mm for the flow into the sump and i guess the fluval nozzel will dictate diameter for return path??

i had though of using a dual pick-up out of the tank, top and bottom (my thinking that the top pickup could be placed at a height to break the siphon in case of power issues) thought off two strainers on one line (like an upsidedown capital F)

using the skimmerless overflow i kinda thought that a valve in the "to sump" line wouldn't be an issue with blockages etc, especially using the strainers i've spotted at bunnings yesterday, and this valve would help set height in the weir (hang on back) http://bellsouthpwp.net/b/u/bullman7/overflow.htm

cheers,

should get off my ar** and draw a schematic to explain a bit easier, :lol:

[suphew]

have been toying with the idea of a spring loaded non return valve in here to prevent back siphon in case of power issues

Don't do this because they are prone to failing. Instead run your return over the top of the tank, just below the water line drill a small hole in the pipe. If the power fails, the tank will drain below the small hole and it will suck in air breaking the syphon.

Your down flow pipe should be at least a size larger than the return pump outlet. And as you know your durso needs to be a size larger again.