Extra large bell siphon

[Island boy]

Has any one tried a large bell siphon ? say with a 3 inch stand pipe and a 6 inch bell ? The grow bed that I want to use is 4 feet wide by 88 feet long.I dont know if i could use one large bell (possibly larger than what I said) or if I should split the bed up in setions and use the standard size siphons. 4000 gallons of fish tanks feeding two 4 by 88 foot grow beds feeding a 12 foot by 80 foot raft section.

[Yabbies4me]

If my calculations are correct, assuming you'll have 300mm of gravel depth, you will have nearly 10,000L of gravel in each grow bed, which will take about 3,500L of water to flood, or 7,000L for the two of them, which is about half your FT capacity… you will need a sump tank IMO… and a big one.

The flow required to start a siphon with a 3” standpipe would be huge. I would break the GB’s down into a number of sections, of probably about 15ft max, each with its own in-flow and siphon. Having a number of smaller GB’s with individual siphons would not only decrease the requirement on your ST, but also increase the frequency with which freshly oxygenated water enters the FT.

Cheers.

[Walks-In-Storms]

If my calculations are correct, assuming you'll have 300mm of gravel depth, you will have nearly 10,000L of gravel in each grow bed, which will take about 3,500L of water to flood, or 7,000L for the two of them, which is about half your FT capacity… you will need a sump tank IMO… and a big one.

The flow required to start a siphon with a 3” standpipe would be huge. I would break the GB’s down into a number of sections, of probably about 15ft max, each with its own in-flow and siphon. Having a number of smaller GB’s with individual siphons would not only decrease the requirement on your ST, but also increase the frequency with which freshly oxygenated water enters the FT.

Cheers.

I tried a two inch pipe (and on down - curious about various kinds of siphons), and I'd suggest following Yabbies' advices. Incidentally, I'm trying to devise a siphon system for my backyard goldfish-koi pond - in order to keep a downpour like a recent one from flooding and letting the fish out to be stranded on the lawn - wonder if anyone here (kindly) has any ideas.

(I've tried a U-siphon and a loop siphon with rather dismal results.)

[scottefontay]

I have built, and am currently operating two 2-inch mega-siphons, 2-inch standpipes with a 2"-4" reducer couple and 6-inch bells. They each operate four IBC grow beds very well. My recommendation would also be to break it up into smaller sections, but not just for the reason of the bell siphon size. You really want to be able to break the growbed into different functional sections - dont' want to have to take the whole thing off-line to service it.

Also within each ~15ft section you should have a central perforated drain line running down the center bed to quickly convey water to the siphon.

[Island boy]

Thanks for your help. In each run I will make 6 sections about 14'6" long with incoming water distributed along the top and not just in one spot.