This is Part 1 of Chapter 8 of the Urban Aquaponics Manual.
“An intermediate bulk container, IBC tote, or pallet tank, is a reusable industrial container designed for the transport and storage of bulk liquid and granulated substances, such as chemicals, food ingredients, solvents, pharmaceuticals, etc.”
So sayeth Wikipedia.
Notwithstanding the uncomplimentary things that I had to say about IBC’s in earlier chapters, I do acknowledge that, for many people, they are the most cost-effective means by which to acquire a fish tank. For that reason, we’re going to use one for this build.
My biggest issue with them is that their shape and structure can be problematic when it comes to concentrating and removing solid wastes. Most of them are not actually square; they’re slightly rectangular. The bottom of an IBC is not flat; it has structural moulding that discriminates against herding all of the solids into its centre.
Suffice to say, if we can make this work, you’ll be able to take what you learn and make any round or square tank work even better.
Our first task is to remove the steel retaining bars to give us free access to the plastic bladder.
Then, we mark up the top in readiness for cutting. Removal of the top allows access to all internal surfaces of the IBC – to give it a thorough cleaning – and for ongoing management.
This particular unit contained glycerine in its former life – non-toxic, water-soluble and easy to remove.
An electric jigsaw is my weapon of choice when it comes to cutting IBCs and other plastic containers.
The dump valve enables the IBC to be emptied and the space immediately behind the valve is a trap for solid wastes. To prevent your toddler (or your sister’s toddler) from operating the valve, we’re going to zip tie it in the shut position. And then we’ll plug up that space behind the valve to prevent solid wastes from accumulating there.
I’d like to be able to drain this tank directly through its bottom but, the pallet arrangement doesn’t easily lend itself to that, so I’ll install a solids lifting outlet (SLO). This is a fancy name for a simple device that uses the weight of incoming water to displace water already in the tank…forcing it up a pipe and out of the tank.
Clear as mud…right? Well, hopefully, this simple diagram will clarify things for you.
We’ll be setting this IBC up so that the solid wastes are directed to the centre of its bottom…so it’s logical that we’ll place the suction end of the SLO over that point.
Before we get too concerned about the SLO, however, it’s time to modify our IBC for its new role as a fish tank.
Step 1 – Remove the retaining bars at the top of the tank.
Step 2 – Mark out a square section to be removed to provide our tank opening.
Step 3 – Cut and remove the plastic top to create the opening.
Step 4 – Mark out the exit point for the SLO – and drill a hole of the appropriate size.
There are two way that I’d propose for the
Step 5 –
Building the SLO is a simple matter of assembling some PVC fittings and a couple of short sections of pipe.
In the meantime, I invite you to comment…to express any concerns that you may have…and to provide ideas or suggestions that you feel will improve the book – or add value to it.