Backyard Aquaponics
A place to discuss aquaponics

@Fishbits - I am still a bit puzzled by this...How do you know the suction doesn't break? If the water drops below the inlet cuts and air is able to enter, (as in media not blocking the vents) the suction MUST break.

So I am wondering if you are thinking suction doesn't break because you still have water dropping into the FT - have you checked your outlet in the bottom of the GB is not leaking? That's about the only think I can think of that would still have water coming out of the GB once air has gotten into the siphon.

This is the new/successful bell siphon currently in operation.

I've been able to get the suction to break enough that it stops draining into the sump at least. Pressure is still in the bell as it still doesn't completely release but once the GB starts to re-fill, the rising water balances pressure out and life is good. System has been running w/o a hitch all day. If it's still going tomorrow AM I may start cycling.

The OTHER thought I have is that the water isn't as clean as I'd like it due to stone not being as well washed as I had hoped. You'd think that 15 min of agitation in a wheel barrow under constant running water and bottom draining would've done the trick.... SO.. I'm thinking of seeing if a whole house filter will function between the pump and the FT w/o messing things up too much. Specs say min pressure for operation is 4lbs. If it works, I figure 24/48 hours running it should clear things up satisfactorily.... Could be a cheap fix @ $20 if it works. Otherwise, things will just have to settle and/or filter out as things grow....

Don't bother putting the 'house filter' on. Just let it run and the water will clear. from time to time disturb anything that may have settled in the fish tank, sump etc and the grow bed will catch it. Eventually it wont be a problem. That's one purpose of the gravel, filtering the water.

Thanks, James... After almost 24 hrs of running I'm starting to see that now. And here I thought that there was just too much dust in there. Wonder what's going to happen when I finally get plants and <gasp> fish in there...

Journeyman, you asked how I knew that the siphon wasn't breaking... Well... I wasn't getting a complete break. Siphon would stop sucking just enough water to stop flowing into the sump tank but the suction wouldn't completely let go as evidenced by attempting to lift up on the siphon bell. In fact, it was so strong that, if I did lift the bell against the suction it would siphon for a few more seconds.... After watching all of the other "working" siphons, given the obvious, immediate and oftentimes audible loss of suction/sucking of air, I ASSumed that those bells completely broke suction whereas mine simply slows to a trickle and stops within 10 seconds or so of the end of the cycle.

Thanks for all of the help folks....

Well... Finally put this issue to bed for good. My sump is outside of the grow room so I've got plumbing passing through a wall. Turns out that I had all of about 1/4" inch of incline between the elbow on the downspout and the horizontal pipe terminating over the sump. Barely enough to notice w/o putting a level on it as it was all of a 2' run. Dang thing starts within 15 seconds and gurgles and completely breaks at the end now....

I was about to chuck the thing and swap over to a timed F&D just to make life more manageable - or at least so I wouldn't have to justify walking away from the time, money and effort that went in to this sudden-onset obsession... Even my FT heaters are working properly now that I swapped out the crappy Chinese ones. Grow room cruises effortlessly at 75* now that I wrapped the two bare foundation walls with insulating reflective bubble wrap, too. Now to start thinking about actual, you know, fish....

YAAAAAY!!! Always good to get a result. So water was sitting in the elbow instead of emptying completely?

AND you now have walls you can pop when you need a lift.

Yeppers, Journeyman. Amazing just how little it takes to totally throw everything off...

I stayed busy with other aspects of the system until this one solution hit me... Even upgraded my reverse osmosis system to 75 GPD. Ran some tube over to the FT. Popped in another shut off and now I can top off with unclorinated/uncloramineated filtered water with a ph of 7.6. I figure the mineral balance can be handled easily when necessary. Hopefully, nothing that a little seaweed extract and chelated iron can't fix now and then.

So here's how things look now... http://youtu.be/a0mNauo_KHk I figure it's kinder to the forum to just post a link to it as opposed to uploading the entire video and eating up space....

Yep... but you can just embed the youtube link in the post... it will just parse through to the Youtube site...

Cool... Thanks, Rupe.... I figured I would be eating up all kinds of bandwidth and/or memory... Shows what I know... And don't

I do not know why people do not refer to this link.
There is another thread that describes a small change that will work with almost any siphon, and it will stop the siphon instantly, each and every time.
The thread is called "Bell Siphon - Tiny Improvement"
See this link.
viewtopic.php?f=8&t=12660


This is another picture of a minor clarification of the design.
viewtopic.php?p=375415#p375415



And this is my latest untested design to start a siphon easily and have any flow rate desired.
viewtopic.php?p=375859#p375859

Because it's not necessary... u-bends, breather tubes, breather tubes with cups on the bottom... none of them are necessary. They may be smart ideas in their own rights, but just not necessary. With bell siphons the K.I.S.S. principle is king.

The first siphon I ever made took me eight re-designs (mostly from the latest "siphon guru" vids on youtube) and nearly two weeks to get it operating properly… in the end it was a “basic” design flaw that was the issue. Once that was resolved all the designs that I had previously given up on also then worked.

IMO all these "improvements" and "latest cure-all designs" are complicating what is a very simple, ingenious device and turning many people off using them.

The most common mistakes made with bell siphons are to do with over sizing the components:

1. Choosing a standpipe diameter that is way too big for the GB capacity... the biggest mistake by far. I have run a 15mm standpipe in a GB with 300L of gravel 300mm deep and had F&D cycles around 25 mins... perfectly fine. A 20mm standpipe gets it down to under 20 minute F&D cycles, normally around 17 mins.

2. Making the bell from a pipe diameter that is also way too big in ratio to the standpipe.

The next biggest mistake made with bell siphons is either not enough back pressure below the standpipe pipe, or too much back pressure, ie: too long a return line back to the FT/ST, or returns that run uphill in parts. Long returns to FT/ST’s should be running slightly downhill and in large diameter, non-airtight pipes.
There should be some back pressure immediately after the siphon standpipe, ie: a 90 deg elbow with a few inches of pipe running out of it horizontally... this can then run into the large diameter, non-airtight return to the FT/ST

The most common mistake with bell syphons is ever using one; unless you have masochistic tenancies. The, I've got one to work is like saying (a) I got lucky (b) I am a total nerd and worked it all out on a spreadsheet or (c) you can beat me as may times as you like but I got pleasure out of it.

My point exactly!...

They are a very basic, simple piece of equipment with no moving parts, they don't rely on timers and are 100% reliable... it's NEVER the auto siphon that fails!

I have one that's been operating for well over two years now and has only stopped twice... neither were the fault of the siphon. The first stoppage was due to my lack of maintenance, the inlets in the pump were partially blocked with bio-film, reducing the flow rate. I cleaned the pump and the siphon soldiered on like nothing had happened. It stopped the second time when the pump snapped an impellor shaft.

I have sold dozens and I am yet to have a customer ring me up and tell me their siphon isn't working. I'm sure some have stopped working for whatever reason, but I do give the customer a 2 minute "bell siphons 101" lesson when they buy one... and that's as difficult as it gets... from there they are able to trouble shoot for themselves... on the other hand, I do have a box with about 12, or 15 dead timers sitting in my office.

P.S. (a) It's definitely not luck, (b) I'm definitely not a spreadsheet dweeb, and (c) I'm definitely not into S&M! (although I sometimes imagine when I'm dealing with the ATO that it might possibly feel the same)... so maybe they just work if built well...

Yea, I do not know what is up with the siphon haters. Mine work great.

Im with you. Its lack of understanding why they don't work, that's all