Backyard Aquaponics
A place to discuss aquaponics

Thanks for the replies.
The siphon pipe attached to the elbow from the GB is even with the top of the 3" drain pipe. Elbow being horizontal with the drain pipe.

That means the end of the pipe is about 4" below the bottom of the GB taking into account the 3" pipe and the drain is below the 1" elbow. There is a "V" cut in the siphon pipe that is inside the drain pipe so it wouldn't bottom out inside and cut the flow. I reckon that would bring us back up to 3" below the bottom of the GB. Make sense?

Adding more water, the cycle does continue, but I was under the impression that the bed was supposed to drain al the way down until the siphon breaks with air entry. These beds drain until they are just under the bottom part of the loop at it's highest point. Goes out with a rush, and right away, slows to a trickle. Then the draining stops and the bed still has 3/4 of the water left.

Kind of like my energy level after I drink my morning coffee. Lots of plans for the day, then no energy after I get started good. Something definitely wrong here. lol.

So, do I try a smaller diameter of siphon pipe, lower the drain pipe even more, make the loops longer, or what?

If the end of the tube is sitting down on to the bottom of the drain pipe... then when the siphon starts and fills the pipe.... the tube probably wont allow air to enter to break the siphon properly...

Maybe fix the exit end of the tube so it's just into the drain pipe and not all the way down to the bottom?

Thought I had that issue taken care of with the "V" notch cut in the exit end of the tube.

I'll give it a shot on both of the GB's and report back.

Messed around with the loop siphons until I got frustrated and wet. Dropped the loop out, the thing works great with the whole pipe kicking water out. Raise it back up and it continues to drain the entire bed. Fasten it to the side, fill it back up, siphon kicks in again and trickles down to nothing again. Leaving 3/4 of the water still in the GB.

Somewhere it is getting air in there and not doing it's job the second time around.

Reading some more on this forum, looks like most everyone else has longer siphon tubes than I do. Haven't seen the ends of the drain tubes though. Do I need a barbed elbow pointed up on the end of the tube inside the drain pipe? Think I may try this when my body resets in the morning.

Kinda cramped on space here in this GH. Don't want to raise the beds up any more due to height restrictions and later on in life, I'll be in a wheelchair. Kinda hard to be harvesting stuff that's grown above your head, eh?

Can't lower the drain pipe any more otherwise it won't drain into the FT.

Going to go read to the kids and grab a beer.

Mate i can totally relate to the frustration

Have you thought about just a stand pipe configuration instead of a loop siphon? Its very simple to use and you cant really go wrong with that.

Use your existing hole in the GB but cut a 90mm or 100mm storm drain in half. But that in as a media guard with holes everywhere. Then a 90" pvc to a stand pipe.

I think your problem there is that you don't have the end of your pipe low enough. You have to have a certain amount of "drop" from the bottom of your bed, down to the level where the water flows out of the siphon pipe.

There’s one of the better pics of my loop syphons.

Never had any problems with them.
It’s also 25 mm loop but with a 19 mm reducer going into the drain pipe.
The water inflow is bit higher that the siphon would cope with but the overflow takes care of it.

I have agripipe at the bottom of the GBs running the full length.

I'm totally new to this stuff, so I don't know much.

But sounds like it's not getting a good enough start. I noticed you have a pretty large circumference along the top of that loop. Have you tried holding a siphon with a tighter radius at the sides of the loop?

In other words, do you get different results with varied shapes in the loop itself? I would be interested in seeing how it acts with the top of the loop shaped more like a pyramid then a dome. --But not actually kinked, of course.

I agree with EB, drop the pvc pipe down lower....it looks as if its level with the bottom of the bed, the lower the pvc and the longer the actual drain loop the more sucking/draining power it will have. IMHO

iammr.bill, just reread few of the posts, what is the hight difference of your siphon loop pickup from the GB and the drain pipe,
the angle that pic was taken may not represent it accurately.
I have 13 cm from the bottom of the loop elbow in the GB to the end of the reducer inside the drain pipe at the far end,
about 15 cm closest to the FT.

I see two problems
a) Water from the loop end must flow out freely, at full speed, the same as it was working when out of the drain pipe.
If inserted fully in, that V cut in the loop hose is not enough.
Cut it straight and insert just enough into the drain pipe to hold in, put a strap around the loop hose to prevent it being pushed in any further.

Can you try it on one GB with water to all the other GBs being tuned off to se if it works.

b) Related to a), with all the siphon loops being pushed fully in the water flow in the drain pipe is slowed down and backed up,
not permitting the water from the siphon loops draining properly.

How many GB are you draining at the same time, can the drain pipe cope with it?
I’m using 90 mm (3.5”) DWV with both IBC FTs, with 6 GBs each but running two pumps, each filling three GB, alternatively,
so only three GB are draining at the same time.
Siphon loops are 3/4” but eventually will change them to 1” with a ¾” reducer at the end.
The four GBs of the TUB FT are draining into a 50 mm (2”) DWV but only two GBs at a time. Loops are 1” with a ¾ reducer at the end.
I would be pushing my luck if draining all four at the same time.

I wouldn’t be considering the loop siphon without an overflow.

The reducer does have the same effect on the flow as in the Affnan siphon.

Sorry for the tirade, hope it helps.

Not a tirade at all. Good info there. One thing I had seen somewhere that stuck in my mind was the reducer that goes into the drain pipe. Considering the Afnan style, this would make sense to give it more sucking power when the siphon kicks in.

MFT to barbed elbow, siphon hose to exit to the drain are all 1" (25mm). Might try the reducer on the exit end of the hose. Still have the siphon hoses. Hate to give up on a concept that should be simple.

Drain pipe 3" (77mm) should be able to handle the load easily enough. Can't drop it down any more without taking my FT out and lowering it down a few inches. Not too interested in that prospect. Not going to raise the pipe any either. Will have to work with what I have.

Thanks for the replies. Keep the thread going. Pretty sure I am not the only one having problems with these things.

Here is the overflow siphon I use on my small system and my backyard system....

they have worked 100% from day one....

Im sure I will have to clear them one day when the roots start to clog them up...

I keep the inlet of the in-tank pipe within 1/4" of the bottom and they break without
problems

I set the water level at about 1/4 of an inch down from the outside top of the 90 elbow..

jT

Sorry, should read "not going to raise the GB's". A bit too much work involved at this stage in the game.

From what I've seen, the loop exit doesn't have to be much lower than the bottom of the GB.

I think the reducer will be the key somehow. We shall see.

Bill, are your barrels filled with media yet???

Looking at your video... I suspect that the inflow into the barrels might to be too fast...

Effectively, while enough to push the air out of the siphon and initiating it.... the inflow is killing the loop siphon action before it can fully drain...

Adding the media would slow the inflow (around the outlet) slightly... and might make all the difference...

You might still need to be able to adjust the inflow and height of the flood anyway....

So try adding a ball valve to the barrel inflows... even without the media.... and adjust until the siphon works properly....

Once you add the media... you'll might need to adjust the inflows again....

Rupe, was using the water hose to fill it up (well water on our farm), so the inflow was the fastest I could make it. Another patience issue I have.