How long should a Bell Siphon cycle take?

[Josiah Sherman]

Hi,

I'm planning out my grow beds and am wondering how long should an ideal water cycle take? (water filling up in the bed, then draining out)

Also if anyone has any thoughts about how big a grow bed should be, I would appreciate any advice. I would like to have them as big as possible, is it possible to have them too big? I would like to have the each about 100 sq. ft. any thoughts?

Thanks,

Josiah

[TCLynx]

How long should a cycle take?  How long is a rope?

To a large extent, it will take as long as it takes, to really vary it much, you need to vary the size of the siphons and the flow rates.

Ideal cycle, no I don't think so.  What is best will depend on the plants and the system and the climate and the season.  I know some plants that seem to do really well on a timed flood and drain cycle with long dry times while other plants do just fine in a constant flood bed.  Siphons are always going to be someplace in between and to tell the truth, many plants don't seem to care one way or the other and only the rare few seem to have a marked preference (which will vary by climate and season.)

100 square feet of grow bed is going to be on the large side and you may find that running such a large bed on a siphon could be challenging.  I'm kinda partial to 100-200 gallon grow beds that are normally between 8-32 square feet depending on depth (I also tend to use deep grow beds much of the time.)  I think timed flood and drain would be the easier way to deal with really large grow beds.

[Josiah Sherman]

Thanks very much!

That really helps me understand why there is not a perfect answer. I think I will make the beds smaller than I had orginally planned, and build some large bell siphons out of 2" 3" and 4" pipe.

If anyone else has any thoughts on this I would like to hear them.

Thanks again,

Josiah

[TCLynx]

What will your media be Josiah?

Really big bell siphons will try to drain a bed very fast but if the water can't flow through the media fast enough you may find that the siphon will drain down the area right around the siphon too fast while the rest of the bed is essentially still half full depending on the size/nature of the media you use.  With 1/2" river rock I don't think you will get away with much more than 1" or 1 1/2" Stand pipe on a siphon. 

[Josiah Sherman]

At this point, I'm planning on using ¾" rock. I'm also thinking about adding a horizontal pipe with lots of holes in it running the length of the bed under the rocks, this pipe would not be connected to anything, but I think it would help the water flow more evenly.