Which prefered siphon drain growbeds??

[steve]

Is there a siphon that is fairly simple and works consistently? Like the idea of a loop. Understand it has problems also. Wonder which size pipe to use for a 4 by 6 by 1ft. growbed.

[Raychel A Watkins]

Aloha Steve

 Thanks for the kind words about my place.  I truly am trusting God to show me what to do.  You are asking about siphons, I use bell siphons right now.  They can be tricky but I found out if you make them the same way each time and then just adjust the flow of water in and away from the siphon I have good results.  I tkink you have to mature into them.

If you watched the last of the video about the meetup you will see Glen Martinez demonstrating what he calls a bucket siphon.  These work everytime and will never flood nor stop.  In the next 2 weeks I am going to arrange to go to Glens and learn how to make it and hope to share it with all It is amazing

[TCLynx]

Any siphon, even the most consistent ones are going to be dependent on flow rates into the bed as well as the water flow rate through the media (which will change over time due to roots and things.)

 

The Affnan version of a bell siphon is probably a good thing for you to look up as it has some advantages making it function at a slightly wider range of flow rates.

 

For something that will function under an even wider range of flow rates, look up a FLOUT which stands for Floating Outlet.  Unfortunately Flouts require more space to work.

[Michelle Silva]

I am glad to see this thread..I had a heck of a time getting my bell siphon to work properly and consistently..and it is currently down with empty grow beds at the moment as I got too frustrated with it! I planned to come back to it when the other projects I'm involved in slow down a bit.

[Lonny Harper]

I would like to see more people give their input here.  What are the problems you have with the siphons?  Are your beds filling too fast causing your siphon to have a hard time breaking the seal?  I haven't built my beds yet.  What kind of siphon should I use.  The all seem pretty simple, so what causes the difficulties?

[Kobus Jooste]

Perhaps it was blind luck but my first bells always worked and I have stuck with them ever since.  I use a fast cascade to aerate with as well, but lately, I have been experimenting with a sand bed with a very simple bottom drain.  It can have many configurations, but in essence, you work with a stand pipe that acts as the height control, and a perforated base to the stand pipe that drains slower than the inflow rate.  If you operate a timed flooding cycle, the bed will fill up until it hits the overflow level of the stand pipe, and once the pump cuts out, it will simply drain away due to the perforated base of the stand pipe.  It is not a siphon at all but cannot fail unless all the perforations clog up or the main drain line / stand pipe configuration clogs up.

 

I have seen some good pics recently of a modification of the siphon that I want to try.  It is a riser pipe to the top of the bed, followed by two 90 degree turns in close succession to send the siphon down to the base of the grow bed again.  It is cut off just before it touches the base of the bed, and the whole lot is protected with a guard pipe or mesh pot.  It is a bit of a hybrid between a siphon and a loop, but it also looks relatively simple and fool proof.  Can't remember who posted the picture but it is in the mix somewhere.

[Lonny Harper]

I remember seeing that one too.  The pipe going down was cut 5/16 from the base.

Kobus Jooste said:

Perhaps it was blind luck but my first bells always worked and I have stuck with them ever since.  I use a fast cascade to aerate with as well, but lately, I have been experimenting with a sand bed with a very simple bottom drain.  It can have many configurations, but in essence, you work with a stand pipe that acts as the height control, and a perforated base to the stand pipe that drains slower than the inflow rate.  If you operate a timed flooding cycle, the bed will fill up until it hits the overflow level of the stand pipe, and once the pump cuts out, it will simply drain away due to the perforated base of the stand pipe.  It is not a siphon at all but cannot fail unless all the perforations clog up or the main drain line / stand pipe configuration clogs up.

 

I have seen some good pics recently of a modification of the siphon that I want to try.  It is a riser pipe to the top of the bed, followed by two 90 degree turns in close succession to send the siphon down to the base of the grow bed again.  It is cut off just before it touches the base of the bed, and the whole lot is protected with a guard pipe or mesh pot.  It is a bit of a hybrid between a siphon and a loop, but it also looks relatively simple and fool proof.  Can't remember who posted the picture but it is in the mix somewhere.

[TCLynx]

Some might call that one an internal goose neck siphon.  I've done something similar to that externally as well sort of like a loop siphon but with hard pvc. 

 

One of the first things I would warn against is trying to balance siphons for barrels cut the long ways.  I have seen them work but they can be far trickier than anything else seeing as the varying volume by depth is going to make the siphon harder to stop as the barrel is almost empty and even harder to start as the barrel is almost full.  If you must do siphons and must use barrels, I would recommend cutting the barrels around the middle to give yourself deeper round beds and siphons will be easier to get balanced right.

[steve]

Thanks all for your input! I will try to build the Affnan version. The extra 8 in. elevation required for siphon to work properly is hurting my design though.  I was hoping for tomatoes, and large plants with lower beds. Any other ideas for a siphon with less head, that works?? I'm working on the cement, and block supports for a ferrocement growbed today.

[TCLynx]

When you say extra 8 inches, do you mean bottom of the grow bed 8 inches above the top rim of the fish tank?  Or are you saying the top of the grow bed 8 inches above the top edge of the fish tank?

 

I have done a grow bed next to a fish tank with the top of the grow bed only about 8 inches above the top edge of the fish tank and ran a loop siphon over the edge of the fish tank but that one was pretty tricky to get balanced.  If the water level in the fish tank was up over the end of the loop it would affect the siphon kicking in or cutting out.

[steve]

Actually I had planned for bottom of farthest growbed to be 5 inches above pond. Which would allow 1/4" per foot for drainage pipe. Under the recommendations for the Affnan siphon. It is suggested to run drain pipe straight down 8" below tank to an elbow. Have a feeling that all his tips could make this all work nice. I see he is working on a high water siphon with breather vent, for higher tank water problems.. 
TCLynx said:

When you say extra 8 inches, do you mean bottom of the grow bed 8 inches above the top rim of the fish tank?  Or are you saying the top of the grow bed 8 inches above the top edge of the fish tank?

 

I have done a grow bed next to a fish tank with the top of the grow bed only about 8 inches above the top edge of the fish tank and ran a loop siphon over the edge of the fish tank but that one was pretty tricky to get balanced.  If the water level in the fish tank was up over the end of the loop it would affect the siphon kicking in or cutting out.

[Lonny Harper]

Another 8 inches question:  I'm building my tanks right now...Do I need eight inches if the bell drains straight down into sump tank?  Is the 8 inches of vertical pipe needed to create the venturi affect?  I might have to re-design my system.  Right not, I Plan on having the grow bed just a few inches above the sump.  I thought if it drained straight out, that it would be okay.  Am I wrong?

[TCLynx]

It will depend on the water level in the sump tank.  I've done siphons where the bottom of the bed is sitting right on the tank below it.  If the water level in the tank below it is over the bottom end of the siphon you might have some trouble getting the siphon to shut off without the breather or snorkel but as long as it isn't a barrel cut the long way you will probably manage to make it work.