Converting an IBC Tote Into A Water Tank

Recently, I put in an improvised water tank. This post outlines the why, and the pros and cons of my chosen solution.

This solution is relevant to gardeners and households who

• Want up to 1000 litres of water storage
• Are confident with DIY at the level of wrapping up an extra-large Xmas gift, and
• Are comfortable with bridging the gap to domestic fittings/irrigation. (see Fun Fact #1)

The stored water is suitable for gardening purposes but should be filtered/treated prior to use in food preparation or drinking.

To keep things focused, I only outline the construction and a couple of key considerations for people new to IBC totes.

For myself, I only have space for two or three units. So in the long-term, commercially-available tanks that are space-efficient and more solid, look like better value.

What Is It?

The main features of the tank are:

• Stores approximately 1000 litres when full
• Captures rainwater that fall on it's roof, though this is offset by evaporation.
• Is independent of the mains supply (underground pipes)
• Is made from food-grade plastic
• Has an improvised filter secured over the outlet, to prevent debris and smaller animals falling inside
• Can be closed off by screwing the inlet cap on
• Can deliver water at very low pressures via gravity feed.
• Works with standard garden hoses and standard pumps, once you have the outlet adaptor.

Why Store Rainwater At All?

Sufficient water is essential to maintain the garden. During summer, I require a substantial volume of water for the garden, which presents challenges for life-as-usual and during any disaster/emergency.

For my life-as-usual, the challenges are increasing cost and potential rationing during drought. The increasing cost is due to both inflation and using more water as the garden grows. There is a history of regional droughts causing rationing of mains water including banning for some gardening.

For a disaster, there is the inherent potential of an outage on the water network from either a one-off leak or a natural disaster. In these cases, the backup supply is for the garden and human needs.

Another particular challenge is the volume needed, being approximately 800 litres per month.

Storing rainwater in bulk addresses these issues, essentially paying for the water in advance. I was challenged to figure out how to store that volume cost-effectively. After considering various options from 'don't bother' to 'pay a lot of money for a commercial tank', I settled on using an IBC tote.

Pros and Cons Of The IBC Tote Method

The pro's of this method is that it is low-skill, cheap compared to other solutions and modular. If I don't need more volume, then I haven't wasted money on unused capacity. Alternatively, I can add another unit relatively simply.

The con's are: thinner walls and a shorter lifetime than professionally-made tanks; makes inefficient use of the ground space; can't 'plug and play' standard fittings.

Note: The cages can be stacked on top of each other, but I've never done it so I don't know how practical it is.

I'm satisfied with the method for my immediate needs, but I wouldn't use it for meeting a households annual needs. That's where I can see the value of a professionally constructed tank(s) that is both space-efficient and trustworthy for the long-term.

Construction

The construction 'process' is essentially wrapping a food-grade IBC tote in black PVC to prevent algae growth driven by light. The actual tank was

• Removed from the cage,
• Wrapped in the PVC, which was secured with PVC tape, and
• Returned to the cage.

The whole unit is mounted on a shipping pallet to keep the metal base out of groundwater/run-off.

The messy top is an improvised rain-catcher, with some random cloth over the hole for a filter (see second picture).

Fun Fact # 1: The outlets on IBC totes use thread sizes unique to the commercial food industry. These are not automatically compatible with domestic gardening hoses and fittings. An adaptor is required and can be found online in NZ. This usually converts to the 25 mm or 20 mm female domestic threading households use. From here, you then assemble the right combination of fittings to use your hose.

Fun Fact # 2: IBC totes use different screw heads than the usual in households e.g. slot, Phillips. You'll need the right one to remove the actual tank from it's cage. My experience is that appropriate screw bits are available at the main chains.

Drowning Risk:

This applies for small animals e.g. cats. The inlet hole on top of an IBC tote has various sizes from 80mm to about 100 mm. Secure a filter/barrier across the inlet to discourage animals etc falling inside the tank.

Conclusion

To me, the IBC tote is a relatively accessible/affordable way to start providing bulk water storage. The main strengths are simplicity and therefore cost. However, it does require the use of adaptors etc to bridge the gap from the tote to domestic irrigation and hoses. The main limitation is that it grows horizontally, so space limits apply. I wouldn't rely upon it for all the water needs of my household - I would prefer a commercial tank with much thicker construction.