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Davi
11-11-2010, 06:00 PM
Hi!, how's things goin with everyone and their aquaponic endeavours?
I'm new to the aquaponics and wanted to ask a question.

When i look at most fish tanks i see a vetical PVC pipe about 5" in diameter at the center of the tank and protruding just about a few inches above the water.

Can someone tell me what this is and what purpose it serves?

Thank you,
Davi!

JCO
11-11-2010, 06:53 PM
Welcome to the show....pull up an easy chair, relax and stay awhile. New voices are always a welcome addition to our family..! Whatever questions you have on you mind, this is the place to get the answers and one of our members will answer your question shortly. Enjoy. :mrgreen:

urbanfarmer
11-11-2010, 10:28 PM
Greetings, welcome, and enjoy your stay!

Most likely you are seeing what is called a Bell Siphon. It is a basic device that leverages physics to facilitate the automation of flooding and draining your grow bed. There are many designs and implementations, some simple and some complex. The basic idea is that it does not activate until it reaches a specified height. Once it does, it creates a siphon and drains out the water down to another specified height. From there, the device is designed to break the siphon so as to allow the bed to fill back up. Flood and drain systems have a serious advantage over other systems when it comes to oxygenation. Even at 8 PPM (parts per million) dissolved oxygen, you can't beat sitting in air, which as you know is 21% oxygen or 21,000 PPM oxygen; that is great for the bacteria and plant roots!

I randomly selected a video on it; check it out and look around:

SBf2cg8f3BQ

Davi
11-12-2010, 08:53 PM
Thnx JCO and urbanfarmer, checkin out that Bell Siphon as we speak!

keith_r
11-12-2010, 08:59 PM
the one in the growbed is usually the siphon, if it's in the fishtank, it's probably a solids lift overflow

urbanfarmer
11-12-2010, 09:11 PM
LOL he DID say fish tank!!! :lol:

Davi
11-13-2010, 08:35 PM
Yes, the one I saw was actually in the fish tank. I looked at the vid that was posted and did some research and saw that the bell siphon is used in the grow beds but the thing i saw was in the fish tank.

What is this solids lift overflow and what does it do. I googled 'solids lift overflow' but didn't get anything.

Thanks
Davi

davidstcldfl
11-14-2010, 05:25 AM
Hi Davi, Water is coming into the fish tank....it leaves the tank by going through the SLO.

It 'looks' like the water is flowing uphill. The water 'does' flow up the long vertical section, carrying solids with it.

The water is actually seeking it's own level....it has to go up the vertical section. Check out the drawing here....
Flow or the water (http://www.diyaquaponics.com/forum/showthread.php?507-Flow-or-the-water)

The top of the tee 'inside the tank' is 'open'....otherwise, it would be creating a siphon.

urbanfarmer
11-14-2010, 01:32 PM
David, I have never told you, but you are a fantastic artist! :twisted:

davidstcldfl
11-14-2010, 03:55 PM
Thanks UF.
I think you might be going out of your way to be kind...or you need to have your eyes checked.. :lol:

I wish I had a CAD program (and knew how to use it).....my monitor has lost one of the primary colors....BUT, I'm an AP addict....all my money goes towards that !..... :oops: .. :roll:

badflash
11-14-2010, 07:20 PM
Just to be clear about answering your question, the device is used to set a fixed level in the tank and to remove solids that collect near the bottom of the pipe. This is sometimes referred to as a standpipe.

Davi
11-15-2010, 05:09 PM
Ok, cool, thanks! but is the SLO/stand pipe necessary for the removal of the solids waste? cuz i was just going to let the outlet of the fish tank be at the bottom center of the tank and have the tank bottom be kinda conical (like how the bottom of some clarifiers are or like a hopper) so that the waste would find its way to the bottom and be sucked in. Would that work?

Thanks!

keith_r
11-16-2010, 06:53 AM
i think that would work, especially if you angle your return lines to give the water a "swirl" affect, that will draw the solids to the middle, and you'll be able to drain it off as neeced

badflash
11-16-2010, 06:09 PM
Yes, it will work, but it isn't a safe way to go. If the drain pipe comes lose or gets a hole in it, the entire tank drains. A standpipe keeps a constant level.

Davi
11-17-2010, 01:40 PM
Thanks guys, i'll research the SLO some more.

Davi
11-17-2010, 02:13 PM
Was checkin out the SLO/standpipe design here:
http://www.rbmaqua.com.au/documents/RBM ... y-_000.pdf (http://www.rbmaqua.com.au/documents/RBMconsultancy-_000.pdf)

Now i've got a couple of questions,
1. if this SLO design is right, doesn't it drain through the bottom of the tank as well, so it it got a leak in it, wouldn't all the water run out?
2. does the SLO pick up solid fish waste well enough?

Thanks
Davi!

keith_r
11-17-2010, 02:28 PM
no, that's not a "slo" drain, but a standpipe.. totally different..

for SLO diagrams (and others), check this thread; (from another forum)

http://www.backyardaquaponics.com/forum/viewtopic.php?f=11&t=5311

Davi
11-22-2010, 01:27 PM
Ok, thanks! Is the SLO powered by air like an Airlift?

keith_r
11-22-2010, 01:58 PM
no,, the slo is powered by gravity.. physics

davidstcldfl
11-22-2010, 02:13 PM
Water is coming into the fish tank....it leaves the tank by going through the SLO.(drain)

It 'looks' like the water is flowing uphill. The water 'does' flow up the long vertical section, carrying solids with it.

The water is actually seeking it's own level....it has to go up the vertical section to exit the tank.
The water comming 'into' the tank, displaces the leaving water.

urbanfarmer
11-23-2010, 01:55 AM
no,, the slo is powered by gravity.. physics
Let's not forget the intermolecular forces that allow for the continuity of the liquid to apply pressure evenly thereby displacing water in a level fashion! :ugeek:

davidstcldfl
11-23-2010, 05:11 AM
The fish pooh is getting deep.... :lol:

Davi
11-23-2010, 05:39 PM
I know i'm kinda slow but i'm trying to understand how the water would run up the pipe when u place it in the tank just like that. I know that it works cuz you guys and other people are using it successfully but i'd like to understand the principle and mechanics of its operation.

Do you have any videos of one in action or literature on the SLOs

Thanks again!
Davi

badflash
11-23-2010, 08:46 PM
Water seeks it's own level. If you put a pipe over another pipe with a gap between the outer pipe and the bottom, the level inside the outer pipe and outside the outer pipe will be very close to the same. If the inner pipe is shorter than the outer pipe, and is has an exit out the bottom, it will set the level in the tank. The only way water can get to the inner pipe is by flowing through the outer pipe. It goes up, but not above the water's surface.

If you want to go over the top, you use a siphon.


I know i'm kinda slow but i'm trying to understand how the water would run up the pipe when u place it in the tank just like that. I know that it works cuz you guys and other people are using it successfully but i'd like to understand the principle and mechanics of its operation.

Do you have any videos of one in action or literature on the SLOs

Thanks again!
Davi