Backyard Aquaponics
A place to discuss aquaponics

The fish tank will only overflow to the grow beds while water is being pumped into it, otherwise it will not drain down below the point set by the venturi drain or no holes overflow (whichever is lower.) This is the safety measure afforded by CLIFT PIST, you can't pump your fish dry.

this bucket grow bed set up will flood and drain while the pump runs constantly since it is fitted with a loop siphon. (A timer can be added into such a system if one wishes, so long as the pump runs long enough to flood the beds so the siphon will start, it can then shut off for long enough for the beds to drain or longer if you like.)

If one wanted to avoid the auto siphon all together, one could simply make a small drain for the buckets and run the pump long enough to fill them with a timer and then shut off for long enough for them to slowly drain. (An overflow is even more important with this method since many timers are not that flexible in their increments.)

Hope this info helps some.

Thanks TC. I think we have it now.

Thanks RupertofOZ. I like the idea of a siphon if aids in drawing oxygen through the GB media. How would I make a siphon? Do you have to just buy them? Where exactly would you put it in the whole flow of things? I had thought the pump would just drain the GB's. Sorry if my questions are simplistic but this is really all very new to me and I want to get it right first time if possible.

Wow EKB! Outstanding! TY!

Hey TCL! Thanks yet again!

I am still trying to understand about siphons. It seems here in your pic that a loop siphon allows you to run a pump constantly - which I have heard reduces wear and tear on the pump as against stop and start. I see a tube... how does it do this? My only experience of a siphon was tubing that you sucked on to get water moving out of a fish bowl in order to do a water replacement. How does your loop siphon work by itself?.... and even seems to act as a timer! Thanks for your patience...

Cyara, here is a great thread on autosiphons (also by LKB)

viewtopic.php?f=8&t=685

That loop out of the bucket is connected to a plumbing fitting that goes through the bucket near the bottom, then the loop comes up and curves around so the end is hanging over the sump. The height of the top of the loop corresponds to the high water level of the flood in the buckets. Essentially, the bucket fills up and the water also rises in the loop, once the water gets high enough to start flowing down the other side of the loop, it acts kinda like you sucking on the tube to start a siphon. It can do this all on it's own because the water is able to flood above the top of the loop in order to start the siphon which then drains the beds quickly. This is the key to auto siphons, they do not go over the top edge of a container, they must exit the container below the high water level in order for them to operate automatically.

Like this Cyara....




As TCL says.... as the water level rises in the barrel... it also rises in the black tubing...

Until it gets to the top of the tubing (your set max water height in the barrel).... forcing/expelling any air out of the tubing....

Water then rushs down the tubing... dragging the water out of the barrel via a siphon action....

Exactly like sucking on the tube.... which pulls the liquid up the tube expelling the air and initiating the siphon....

When the water level drops and air re-enters the siphon tube, it breaks the siphon affect...

Here's a bodgey trial run I did... filling before the siphon initiates...



After the siphon has completed... water level is below the outlet valve, allowing air to re-enter the tube....

Given the density of great info in this thread, it might be worth a sticky.

Or you can check out the process of discovery that steve went through to find out how loop siphons work in this thread. Truly enlightening.

Or check out Simmo's threads on looped siphons...

viewtopic.php?p=14382#p14382

viewtopic.php?t=470


Or Joels....

viewtopic.php?t=160

What superb simplicity! Thank you so much for all the explanations. Greatly appreciated!!

From what I've read here the water flow is fish tank -> grow beds -> sump -> fish tank.

Would you ever run fish tank -> sump -> grow beds -> fish tank? And, if not, why?

Depends where you're pumping from and how many pumps healingdeva...

If, in your scenario, you were pumping from the tank to the sump and then pumping the sump to the growbeds... and the sump pump failed....

Then the tank pump would continue pumping... overflowing the sump.... until the tank was dry... dead fish, and (because no pumping to growbeds from sump), suffering plants....

Just one scenario .... that's the beauty of chift pist... pump from sump to tank to growbed..... eliminates points of failure.

Oh.... forgot to mention.... we utilise the growbeds to oxygenate the water returning to the tank....

In your scenario.... you'd have to have the growbeds above the tank level.... acheivable if you say, bury the tank....