Backyard Aquaponics
A place to discuss aquaponics

I've got 2 IBCs that I plan to run independently. I was planning on simply pumping directly from the tank below up into the GB above, and using a standpipe to drain straight back into the IBC. This would happen on a 15/45 minute cycle.

Given the FT is about 650L, and the GB 350L, I expect about 150 - 200L to be transferred from the FT to the GB at most. Is this feasible, and how many and what diameter standpipes should I use? Also, what size pump?

Anyone out there running independent IBCs care to let me know how they set theirs up?

As you said will work fine, you'll need around a 2000 lph pump, preferably a 3000.

I would go with one of these:
http://www.rockaroundtheblock.com.au/product.asp?pID=608&cID=63

I bit expensive, but 99.9% reliable for me so far. Very good power consumption. I would swirl any excess water back into the tank via a tap to keep it clean.

fittings can be purchased to alter the coarse thread on the outlet to 2" BSP.
if you want to stop fish migrating out of your tanks, then the internal dimension of the outlet is 40mm or there abouts.
So either 40mm PVC, or a 40mm PVC fitting of some kind will fit snugly inside, allowing you to add a fish filter.
two of my tanks required a fitting that fit inside 40mm pressure PVC, the other required a fitting that fit outside 40mm pressure PVC. I'm told that some others fit 40mm pipe exactly.

Doesn't answer your discrete questions, but I thought handy tips regarding plumbing.

Also: use the largest pipe diameter you can afford.

I have a Jeboa 6000 in my fingerling tank through 40mm pipe back to fishtank, they look plastic and cheap but do the job well

Brere