Backyard Aquaponics
A place to discuss aquaponics

Here's an update on my aquaponics setup using 2 utility sinks as a grow bed.
This is the 3rd change to the setup.
I decided to try an external bell siphon setup because i had problems with hydroton sneaking past my guard and getting lodged in the bell siphon.
The drains from both grow beds flow into the external bell siphon.
There are a lot of plumbing connections and parts involved with this setup so there are a lot of leaks. I'll definitely have to PVC cement everything on my next version.

Very imprezzive!

Damn, I'm now having trouble with this setup after adding hydroton in.
The siphon start up isn't as consistent and strong any more.
I'm thinking it definitely has something to do with less water weight to push the siphon to start.
Can someone confirm this? or have any solutions?

Less water in your growbeds now or something is blocking its path out.

Can you increase the delivery rate to your growbeds?

what is the outlet size 20mm? Try this, cut a piece of 15mm pvc tube or similar and shove it down the stand pipe . Dont know how it works but it does. the water backs up behind the 15mm reduced outlet and the syphon begins. if you have less flow for some reason it is a solution. try it no major alterations necessary

@arbe: I can't really increase the flow into the growbed, unless I buy a new pump.
@bluefin: i'm in the US so I'm in inches. My outlet size is 1 inch. I'll try your suggestion and bring it down to 3/4.

Thanks for your help guys.

I think what Arbe was suggesting was to increase the water in your GB. You can do this by just pouring water in from a bucket and see if that triggers off the siphon.

oh, I tried pouring water into the grow bed.
It still didn't trigger the siphon.

Bell is not touching top of standpipe? Has to be couple of inches clear.

kinda hard to tell... how are your beds draining into the external siphon? you might need to provide a little more initial volume by putting a small media guard from the drain to just above the surface of your media... i know it kinda defeats the purpose of the external siphon.. but there's quite a bit of "drag" around the media to the drain.. you might try a smaller guard,, maybe start with 1.5" or 2"

I don't have a photo of my media guard, but essentially it's just pvc cap that fits/blocks the drain from the inside of each utility sink (grow bed). I drilled a LOT of holes into this cap to provide enough drainage but still act as a guard.

Here's a photo of how each growbed drains into the external bell siphon.
Note that the drains sit higher than the low-point of the siphon.

Also, my bell has about a 2 inch clearance from the standpipe.