Backyard Aquaponics
A place to discuss aquaponics

Sorry to be picky FF, but can you take the first two photos but without the black pipe in the shadow? It makes it hard to see where it goes.

Does the bit of poly strapped to the side have a solid cap on the end? The primary flow looks like it's through the main vertical tube up through the cranulations and the piece strapped to the side breaks the syphon once the small cap/tube bit strapped to the side is emptied?

It sucks being a hands on pull it apart type and trying to garner information via a medium like this - i get bloody frustrated!!

Chatty

Yes i noticed the shadow after i posted them. Sorry about that. It sounds like you understand what its doing though. The small pvc bit on the bottom has a cap and works like a timer it empties whilst the rest of the water level drops and then raises as the outflow becomes less than the inflow to the GB. This buys a few seconds for the syphon to suck air and the clear vent pipe to let some air into the cap to prevent a follow on as the water level rises again. Without it the syphon would slow to the same rate as the inflow to the GB but not always stop completely or if it did it took a few slurps and wasn't quiet enough to have stuck outside my bedroom and next to the neighbours fence.
That syphon is a 50mm sewer inner and a 75mm stormwater outer, the bit stuck on the side is 40mm pressure pipe but it could have been a coke bottle or anything like that. The syphon empties the growbed in the same amount of time it takes to fill so it must be around 6000l/hour as this is twice the inflow from the fish tank.

Let me get this right... So the bottom of the black poly is at the same level as the top/bottom of the crenulations on the main (75 mm) tube? A smaller diameter pipe makes it easier for a gutfull of air to be sucked up into the siphon to break the airlock?

Presumably the black tube sucks water out of the 40 mm poly tube quicker than the main siphon empties the bed. Does it then 'leak' water out of the siphon back into the 40 mm tube to refill it and maintain the siphon action??

Questions, questions

Chatty

Black poly goes all the way to the bottom of the 40mm cup so that it sucks it dry. Yes it sucks out the water faster than the main tube empties the area around it. No it doesn't drain back and refill, it refills when the water level rises again around the whole thing.
The syphon stays primed because there is an upturn on the end of the pipe to the sump that holds some water creating an airlock, that will then get pushed out when the pressure gets great enough behind it. My top cap of the syphon gets about 10mm underwater when it starts and this with the GB filling to 20mm from the surface.

I know I'm dragging up an old post. But...

How's it all fairing now?

Looks fantastic!

Edit...

I should also add, you've just helped me win an arguement with my wife to let me up an aquaponic setup out the front!

Woo!