PDA

View Full Version : New Backyard system bell sypon won't break



rangebob
02-24-2013, 04:59 PM
I started up my new garden last weekend. I had 2 concrete mixing tubs that I'm using for my grow bins. The one I was going to keep with water constantly in it and let it just drain out and the other was going to be a bell syphon. I had the bell syphon running with about 1/2 the pea gravel in the bin with no problems. Today I finished filling the bin and the syphon stopped working and the syphon wasn't breaking the sypon and kept gurgling. What went wrong since I added the rest of the rocks? This is the drain and syphon.https://dl.dropbox.com/u/43119073/2013-02-24%2018.07.39.jpg

bsfman
02-24-2013, 05:10 PM
I started up my new garden last weekend. I had 2 concrete mixing tubs that I'm using for my grow bins. The one I was going to keep with water constantly in it and let it just drain out and the other was going to be a bell syphon. I had the bell syphon running with about 1/2 the pea gravel in the bin with no problems. Today I finished filling the bin and the syphon stopped working and the syphon wasn't breaking the sypon and kept gurgling. What went wrong since I added the rest of the rocks? This is the drain and syphon.https://dl.dropbox.com/u/43119073/2013-02-24%2018.07.39.jpg

Could be two things: #1 water input too fast. #2 the bell looks way too big for the size of the standpipe. This makes it hard for the little standpipe to drain fast enough to empty the bell.

JCO
02-24-2013, 07:28 PM
Just a quick look from the photo, I think it has to do with the way you notched the stand pipe. Can't be sloppy. Sorry for calling attention to it and using the word sloppy, no offense meant. Aquaponics isn't rocket science but you do have to be precise in what you do for it to work correctly. :mrgreen:

bcotton
02-25-2013, 07:58 AM
JCO,

i dont think water cares if the notches in the stand pipe are square or jagged.

rangebob,

is the 4" tube free standing or did you silicone/adhesive it to the grow bed? My grow beds have a similar issue and i have attributed it to the fact that water level cant get low enough to break siphon. Hind sight i would cut slits all the way to the bottom of the pipe and wouldnt silicone the casing down, just secure it using the media so water could seep underneath the tube itself.

The short answer is what bsfman said, it is likely be a too much flow. The difference is the gravel. Water doesnt flow through the bed as fast. So it's slower to start draining and slower to stop.

If your bell isnt configured well your "working window" between too much flow and too little flow may be so small that it's difficult or impossible to achieve. I find it helps to have a little wider entrance on your stand like maybe a 3/4" to 1/2" converter at the top. Also, i cant see the bottom of your siphon but an elbow as soon as possible seems to always help.



brian

JCO
02-25-2013, 10:32 AM
Speaking from experience about jagged and/or rough cuts, if the siphon can suck the slightest amount of air before it gets to the designed break point and the pump is pumping enough to compensate for it, the siphon will not break. "That's my story and I'm stickin' to it" :mrgreen:

bcotton
02-25-2013, 12:21 PM
JCO,

thanks for clarifying, I can see that as a possibility and could see it being at least be a contributing factor.

The fact it worked before the media was put in seems to be the hmmmm dinger.


brian

rangebob
02-25-2013, 05:15 PM
I did another modification that I will be using on the remaining pipes. I placed a hole in the cap and placed a piece of air tubing in it and kept it at about 1" off the bottom of the bed and it is breaking now. The 4" does have cuts all the way down to the bottom of the bed and is about 1/4" apart from eachother and it is on 4 sides. The pipe isn't glued down it is just sitting there. I may try the stand pipe with horizontal slits on the next one first.

I had the same size stand pipe 2" with a 3/4" drain and I couldn't get that to sypon at all no matter what I tried.

I may try the same type of setup to see if I can get the 1st bed to start to drain. Right now it is a constant flood. The standpipe that I did on that one I did nice square cuts and made it look pretty and the second the sloppy look worked much better. I'll stay with the sloppy.

Lordshandyman
02-25-2013, 09:33 PM
I just got my second growbed up and running and both beds quit syphoning. I had to switch back to the big pump that I had replaced in the beginning, as with only one bed, couldn't get the syphon to break (too much water flow) so I bought a smaller pump. But with two beds, the smaller pump just couldn't feed the water fast enough... Put the big pump back on, and bingo, both beds worked beautifully. Actually, the smaller pump would be just fine, except I plumbed my drains with 1 1/2" pipe, so it really needs the higher volume water flow. I might replace my stem pipe with 1" and see if I can go back to the smaller pump, as my system cycles a little more than I would like.

So for me:
No syphon, means not enough water flowing into bed,
No syphon break, too much water flowing into bed.

keith_r
02-26-2013, 06:35 AM
Lordshandyman, you could just use the bigger pump, just divert some of the flow back into the ft, gives the benefit of adding aeration as well moving the water

Bob Vento
02-26-2013, 08:27 AM
I have been using this quick and simple bell siphon flawlessly for over a year now. Thought I would share the video that inspired my use of this technique ...

https://www.youtube.com/watch?v=oDzcKgWLRf0

Lordshandyman
02-26-2013, 05:09 PM
Lordshandyman, you could just use the bigger pump, just divert some of the flow back into the ft, gives the benefit of adding aeration as well moving the water

Yea, I do actually. I pump directly into the fishtank. Have a SLO into the beds, and a backup overflow back into the sump. What happens is the 2000 gph pump is so strong it actually floods my fishtank, even with both overflow drains working! So I have a valve in line that I tone down the pump. I suppose I could put a tee between the pump and fishtank to relieve the extra, but both ways seem to be wasting energy. My overflow already aerates as well as my two gb's draining. I bought the 2000 GPH pump with thoughts of pumping water on my roof to heat it and would need a strong pump... but I decided that would be a project for another time. Had I foreseen the drains being too high, I would have not been so greedy as to gain every last cubic inch of IBC fishtank by putting the drains as close to the top of the tank as possible. I should have put both drains a little lower from the top... As the water gets over them, they would create a suction and drain fast enough, but my current setup this only happens as water trickles over the top at the same time.

Seems like I remember reading somewhere on this forum your pump should be the same size as your fishtank volume. Ex: 300 Gallon Fishtank, 300 GPH pump. This should give a cycle time of 4 flood/drains per hour. So my 560 GPH pump should be a little overkill too. Actually, the 560 gph pump was giving me more cycles per hour than I wanted with one gb... not for sure how many, but way more than 4. And, when I would try to close the inlet valve to slow the water down, I would not get the syphon to start. Now that I have halved the water to each bed, there still is not enough flow to cause a suction. Oh, I should mention that the 560 GPH pump is actually rated 430 GPH at 5 feet high (my current setup). Oh, and my growbeds are 3'x8'x1' with gravel medium. I figure that each growbed holds 180 gallons with no medium. As to how many gallons with the gravel in it, I have no clue. I use 2" pipe for the overflows into the growbed and sumptank.

Here is my theory.... I used way too big of drain pipe. 1 1/2" pipe requires a massive amount of water to flow before kicking in a syphon. And if I have this massive amount of water flow, then my cycle times are way too fast. And if I try to slow the flow to adjust my cycle times, no syphon. If the size to syphon ratio is proportional, I estimate that I should have used 3/4 drain. I think I will test this theory this weekend. Here is my test procedure, let me know if it is flawed!

I shall put the 560 GPH (430 GPH adjusted) pump back in and shut off the extra bed (no plants growing yet).
In the bed that is operational, I will open the inlet valve to full blast so all the water from the pump goes to the bed and not overflow back into the sumptank. I shall buy a 1 1/2 reducer of various sizes for my stem pipe in my bell syphon:
1 1/4", 1", 3/4", and even 1/2" even though I doubt the 1/2 will work well.
My thoughts are that reducing my stem pipe to various sizes will produce different cycle rates (if even at all) even though my drain pipe to the sump tank remains 1 1/2" and my inlet flow remains constant at 430 GPH. Also, that if I find that a 3/4" stem pipe works the best, I figure that a complete drain system of 3/4" would work the same. So any future beds or systems that I make could be plumbed in 3/4" with confidence.
My goal is to find what size drain creates the best syphons at a certain volume. This in turn will help with determining the most economical pump to piping ratios saving more money up front and in the long run. I shall try to tame the cycling beast once and for all.

I suppose I should ask if anyone has done any studies as to what volume of water flow creates syphon at what size pipe?

bbikebbs
02-26-2013, 09:50 PM
... snip ...

Here is my theory.... I used way too big of drain pipe. 1 1/2" pipe requires a massive amount of water to flow before kicking in a syphon. And if I have this massive amount of water flow, then my cycle times are way too fast. And if I try to slow the flow to adjust my cycle times, no syphon. If the size to syphon ratio is proportional, I estimate that I should have used 3/4 drain. I think I will test this theory this weekend. Here is my test procedure, let me know if it is flawed!

I shall put the 560 GPH (430 GPH adjusted) pump back in and shut off the extra bed (no plants growing yet).
In the bed that is operational, I will open the inlet valve to full blast so all the water from the pump goes to the bed and not overflow back into the sumptank. I shall buy a 1 1/2 reducer of various sizes for my stem pipe in my bell syphon:
1 1/4", 1", 3/4", and even 1/2" even though I doubt the 1/2 will work well.
My thoughts are that reducing my stem pipe to various sizes will produce different cycle rates (if even at all) even though my drain pipe to the sump tank remains 1 1/2" and my inlet flow remains constant at 430 GPH. Also, that if I find that a 3/4" stem pipe works the best, I figure that a complete drain system of 3/4" would work the same. So any future beds or systems that I make could be plumbed in 3/4" with confidence.
My goal is to find what size drain creates the best syphons at a certain volume. This in turn will help with determining the most economical pump to piping ratios saving more money up front and in the long run. I shall try to tame the cycling beast once and for all.

I suppose I should ask if anyone has done any studies as to what volume of water flow creates syphon at what size pipe?

I use a 2" down tube with a 1 1/4" reducer under the grow bed. I found that reducing under the bed made all the difference for me. I put an elbow and a short (6") length of pipe after that to help after watching Afnan's siphon videos. This has worked flawlessly since last May. Cycle times are 10 minutes to fill and 1 minute to empty. If you want to slow things down, try a 2" to 1" reducer.