Sump tank questions

[Lorraine Kohout]

I'm in the planning stage of my first aquaponics system. I have three 330 gal IBCs and will use the CHOP2 system with bell siphons. If I have two sump tanks with 2 grow beds each emptying into them, will the bridge siphon keep up with the pump in the first tank? The sump tanks will be two feet apart.
Also, how do you figure the volume for the sump tanks? I will probably build my own out of wood with a pond liner. They need to be short and narrow to fit under the grow beds. Any suggestions will be greatly appreciated. Thanks

[R.K. Castillo]

Why not just do 1 sump tank?  And flood and drain the beds into the one sump?  

Or simply connect the 2 sumps with a pipe?

[Randy]

I have a 100 Gal sump with 110 Gal of gravel bed and it works well. Keep in mind that you need enough volume in the sump to fill all the beds at the same time with some reserve even if you are using bell siphon because they sometimes decide not to start. Another thing to keep in mind is how high is the inlet to the pump. The volume of water below the inlet might as well not be there. I would also recommend one sump if possible, a bridge siphon will break at the worst possible time. When it does your pump will run dry and a lot of water will be pumped on the ground. 

[Lorraine Kohout]

You are both right. After just watching the DVD "Murray Hallam's DIY Aquaponics" (purchased from The Aquaponic Source) I think I will just use the bottom part of one of the IBCs for the sump insstead of making it another grow bed. (I haven't cut any of them yet.) Now I need to figure out how it will fit in my greenhouse. It has support poles down the middle, so it's a little more difficult.  Thanks again.

[Jon Paul]

a 12"-14" deep IBC grow bed with Hydroton as media will hold about 25 gallons of water.