Backyard Aquaponics
A place to discuss aquaponics

Why have a siphon at all if you're already running timed flood and drain? It's an added level of complexity (read: another point of failure).

Simply drill some drain holes in the base of the standpipe to allow the bed to drain under gravity when the pump is off. Start by drilling one, say, 6mm hole and time how long it takes to flood AND drain the GB. If it's too slow to drain, then add another hole, and repeat the test. If you get to 4 holes in a 25mm/1" pipe and the bed is still not draining fast enough then upsize the drill-bit to, say 8mm and rebore the existing holes; but you'll need to balance the time to flood the GB too. (No point having a bed which will empty in 15 minutes during a test through a massive drain hole, if that drainage never allows the bed to fill in the first place!)

There is some maths which can be done, but generally, it's easier to do the test!


Scott