Backyard Aquaponics
A place to discuss aquaponics

Currently using a pair of IBC's tied together, and have a third cleaned and ready to go in the garage.

Everytime I look at what a single or a pair of bigger aquaculture tanks would cost, I go back to IBC's. Upgrading my garden this year... I've learned some of the things to look for as far as water flow and solid pickups by using two tied together. Anyone have advice on putting four or six IBC's together as fish tanks?

Same thing with building a larger raft and media beds. Want to get rid of all the IBC halves and build some beds and line with dura skrim.

I wouldn't necessarily plumb them together, then you are just sharing waste, I'd have each run to GB's or filters. Plus if you ever want to isolate etc, each on its own would be easier

If you plumb them together sharing the water and everything:
Advantages
Your system's tolerance/buffer to pH, ammonia, nitrit and nitrat spikes will be wider.
You may get away with less water pumps.
New GBs will establish the bacteria faster and become functional in no time.

Disadvantages
As this is a closed loop system, if (touch wood) something bad happens, all the tanks and fishes will be affected.
If pH goes out of optimum levels, it will be harder and longer to adjust.
It will be relatively harder to calculate the total water to find out how much NaCl, KCl or HCl you need.
If the fishes travel from tank to tank, adjusting the feed ratio would be harder
If there isn't enough circulation in IBCs, the solids may collect on corners. You may need to address this with an air lift deep cleaner hose.

These are things I can think of.

In my first system I had 3 ibc.s plumbed together it ran for 10 years with very little trouble
After woods I added another remote one and another tank as well 5000 litres total fishtank volume

My uniseals will arrive today. Two I have tied together now were building up solids until I went to a properly sized pump. But then... I discovered the importance of properly sizing pipes. I simply went to a larger outflow pipe, and made a U shaped 2" pipe filled with water to keep both level. When I move them, will up the pipe size to better handle the volume of water. Original design used bulkhead fittings, then I discovered Uniseals.

Moving the exiting system before expanding it will be a challenge, and I appreciate the pro's and con's given. My current unit with 2 IBC tanks has been running for almost 2 years.