Backyard Aquaponics
http://byap.backyardmagazines.com/forum/

Siphon not breaking
http://byap.backyardmagazines.com/forum/viewtopic.php?f=8&t=11483
Page 1 of 1

Author:  Jackfrost [ Jan 7th, '12, 11:41 ]
Post subject:  Siphon not breaking

I finally went and got myself a decent pump today but now I have a problem of the siphon not breaking when it reaches the 6mm at the bottom of the standpipe because (I assume) the inflow is great enough to keep the pressure within the bell if that makes sense. I've considered two options:

A) drill a second 6mm hole in the bottom of the standpipe
B) install plastic tubing from the top of the bell to within an inch of the bottom of the GB

Any of you physics boffins able to point me in the right direction?

Cheers

Author:  Erich [ Jan 7th, '12, 12:21 ]
Post subject:  Re: Siphon not breaking

Firstly - you dont need plastic tubing to break a siphon - ever, you have a water volume issue

Just remember this:

If the siphon will not start there is not enough water flow.....if it will not stop there is too much

If it will not break, you need to regulate it - tap etc

:D

Author:  Jackfrost [ Jan 7th, '12, 15:27 ]
Post subject:  Re: Siphon not breaking

How about a spray bar to reduce the amount of water heading up to the GB and aerate the FT? Would it be as simple as a T just after the pump and sprinkler nozzles screwed into poly pipe (I am already using poly rather than flexible pipe)

Attachments:
Spray bar idea.JPG
Spray bar idea.JPG [ 17.6 KiB | Viewed 4409 times ]

Author:  mantis [ Jan 7th, '12, 15:33 ]
Post subject:  Re: Siphon not breaking

Yep that would work, but a simple pvc ball valve on the return would regulate it.

Author:  Erich [ Jan 7th, '12, 18:06 ]
Post subject:  Re: Siphon not breaking

What Mantis said ;)

again - dont make it more difficult than what it is -

If the siphon will not start there is not enough water flow.....if it will not stop there is too much
:mrgreen:

Author:  Jackfrost [ Jan 8th, '12, 10:13 ]
Post subject:  Re: Siphon not breaking

Erich wrote:
What Mantis said ;)

again - dont make it more difficult than what it is -

If the siphon will not start there is not enough water flow.....if it will not stop there is too much
:mrgreen:

I don't have an air pump though so a spray bar would compensate for this

Author:  Jackfrost [ Jan 9th, '12, 22:59 ]
Post subject:  Re: Siphon not breaking

So it turns out the spray nozzles don't reduce the pressure enough as well as suffering blockages in any case which would reduce their effectiveness so I am going to have to install a valve to reduce flow to the GB. I didn't want to put pressure on the pump so I have come up with the following design. The two advantages are that it will not put back pressure on the pump and that the excess flow will flow back into the FT and create further aeration.

Attachments:
Spray bar idea.JPG
Spray bar idea.JPG [ 19.39 KiB | Viewed 4328 times ]

Author:  Stuart Chignell [ Jan 10th, '12, 03:41 ]
Post subject:  Re: Siphon not breaking

How long is the tail on your siphon? Specifically what is the vertical fall from the bottom if the gb to where the flowing exciting the gbreaches atmosphere?

Many syphons fail to break because they don't have a big enough fall.

Author:  Jackfrost [ Jan 10th, '12, 09:24 ]
Post subject:  Re: Siphon not breaking

Wouldn't be more than an inch, basically just enough pipe to go into the elbow joint. This sounds about right too as it kinda gurgles like it's about to break and then fill back up again. Unfortunately the only option I've got of dropping it further is to put a hole in the side of the FP but that's no bigger I suppose and will be used when I eventually convert my system to CHIFTPIS

Author:  earthbound [ Jan 10th, '12, 10:28 ]
Post subject:  Re: Siphon not breaking

If your holes in the spray bar are getting blocked and not allowing enough water pressure through them, then the holes are too small... Drill them out with a larger bit... :thumbright:

Author:  Kangaroodog [ Jan 10th, '12, 13:22 ]
Post subject:  Siphon not breaking

What about the issue of the spray bar pumping solids back in the tank?

Author:  earthbound [ Jan 11th, '12, 12:10 ]
Post subject:  Re: Siphon not breaking

Not an issue for me coz I don't do it..... :)

Author:  orcy2010 [ Jan 12th, '12, 10:03 ]
Post subject:  Re: Siphon not breaking

Kangaroodog wrote:
What about the issue of the spray bar pumping solids back in the tank?


they just get circulated like everything else. I wouldnt stress too much, its more important that the system actually functions.

Page 1 of 1 All times are UTC + 8 hours
Powered by phpBB® Forum Software © phpBB Group
https://www.phpbb.com/