A little while back, we built a 20 gallon garbage can rain barrel, and it suited our small gardening needs at the time. Fast forward several years later, we’re growing many fruit trees in the backyard, a planter box full of herbs, peppers and tomatoes, a dragon fruit trellis, some sugar cane, you name it! Needless to say, if I still wanted to harvest free rain water, then a 20 gallon rain barrel was not going to cut it anymore.
Why aren’t my plants growing?
I’ve been having difficulties lately growing some of the fruit trees. Their growths were being severely stunted, even with fertilizing. Eileen did some research one night and thought it might be a watering problem. We discussed several theories with my dad (who’s been very successful in his garden), and compared our struggling garden to his very prosperous garden.
Comparing my garden to my dad’s prosperous one
My dad recently installed a well pump with an automatic sprinkler system that waters his plants every day. Since then, he has noticed a significant improvement in plant growth. He attributed it to the volume of water the plants have been getting lately.
I too have an automatic watering system (via a network of irrigation tubes connected to a timer), but mine was connected to city water, and not a well like my dad’s setup. Two things stood out when we compared our configurations. He was giving his plants an abundant amount of free well water, and his water was natural and chemical free.
City water just wasn’t cutting it
In contrast to my garden, I was using just enough city water to keep the plants going (to maintain a manageable water bill), and my water had chemicals (chlorine added by the city to ensure safe drinking water). I thought that natural rain would supplement my city watered irrigation and keep my plants hydrated enough to grow well. Yet my struggling plants told a different story.
Eileen and I both came to the conclusion that we needed a lot more natural and chemical free water for the plants. A well pump was not an option for us due to cost and other factors (like the naturally dissolved smelly sulfur in the underground water in this area).
We need large amounts of natural rainwater
So here’s where the idea of a new and improved rain barrel sprung from. As I mentioned earlier, the 20 gallon rain barrel we made years ago would barely make a dent in our current watering needs. My dad brought up the idea of a used 275 gallon IBC tote. Whoa! He had me at 275 gallons. I had never even heard of IBC totes before, so I quickly looked them up.
275 gallon IBC tote, you’re my new friend
IBC (short for intermediate bulk container) totes are industrial grade containers used for storing mostly liquids. They are essentially large plastic containers enclosed in a metal frame, allowing them to be moved around with forklifts. They come in a variety of sizes, but generally starting at 275 gallons
Tips for finding cheap 275 gallon IBC totes
Lately, IBC totes have become really popular for repurposing as water storage tanks for rain harvesting. Industrial complexes are always looking for easy ways to dispose of their empty IBC totes, and so many plant managers sell the used IBC totes for local pickup.
A quick search on my local Facebook marketplace revealed a number of industrial plants selling IBC totes for relatively cheap prices (around $100 per IBC tote). Brand new totes sell for thousands of dollars,so a hundred bucks for a used one was a steal.
Now, I had to be extra careful that the IBC tote I was buying was food grade quality. Industries can transport almost any type of liquid in IBC totes, ranging from water to corn syrup to detergents and other chemicals. Since I’d be using the IBC tote to store rainwater for plants (and possibly for consumption in emergencies), I definitely wanted one that only ever transported food related products.
Food processing plants frequently sell off used IBC totes
I was lucky enough to find a nearby food plant that was selling their used IBC totes. This particular food plant made things like salad dressings and condiments. I spoke to the plant manager there (who placed the listing on Facebook marketplace) and he said that the latest batch of IBC totes being sold at his plant were used to transport sugar cane juice. In fact, they had only just arrived a few days ago, and had since been cleaned out before putting up for sale.
I was ecstatic to hear this news. These were practically brand new IBC totes selling for only a hundred dollars. I inspected the IBC tote and it was in near mint condition. I paid the man right away, and arranged for a friend to help me transport the IBC tote with his pickup truck. There was no way an IBC tote would ever fit inside a car or minivan. The empty IBC tote was pretty light, so we were able to easily lift it up into the back of his pickup truck.
Preparing for an IBC tote rainwater harvesting system
With the IBC tote acquired, now lay the remaining tasks of planning how to fill it with rainwater. I scouted an ideal corner of the house that gushed with roof water every time it rained. There were no gutters installed at that part of the house, so it was a constant Niagara Falls situation back there.
Coming up with a rainwater harvesting plan
The overall plan was simple. I was going to mount some gutters along two inside edges of the corner. Then somewhere close to the center would be a gutter downspout, that emptied into the IBC tank. I also wanted the tank resting on a stand, as high as possible, to generate some extra water pressure from gravity.
3D design of the IBC tote’s wooden stand
As with most projects of mine, designs start off in TinkerCAD (a free 3D drawing website).
I came up with a relatively simply combination of 4×4 and 2×4 pressure treated wood. My stand was inspired by designs made by fellow gardeners already holding full IBC totes of water. So I felt very confident that the six 4×4 legs of the stand would be able to support the almost 2300 pounds of water that would fill the IBC tote.
Using a first flush diverter for reducing contaminants
For the gutter configuration, I decided to integrate a first flush diverter. I wanted the water in the tank to be as clean as possible. Not only for the plants, but I planned on using the water tank as a backup water supply for the household in the case of emergencies. We lived in hurricane territory, so I slept very comfortably at night knowing that we had a backup reservoir of water during potential city water outages amidst future storms.
So what’s a first flush diverter? Well, imagine when some rain first starts falling. There will no doubt be some contaminants sitting on the rooftop (loose roofing material, leaves, dirt, bird poop!) These contaminants get washed off the side of the roof during the first few moments of a rainfall. With a water harvesting system in place, that means these contaminants will get washed right into the water storage tank. A first flush diverter significantly reduces the amount of contaminants in your storage tank during this “first flush” of the roof.
With a first flush diverter in place, the initial gutter water (potentially loaded with lots of roofing contaminants) gets diverted away from the main storage tank and into a temporary holding area (such as a capped 6 foot section of 3” PVC pipe). Only after this temporary holding area gets full, then water starts filling up the storage tank directly. The holding area typically has a slow drain that empties the contaminated water over time.
There are DIY instructions on the internet for building your own first flush system from scratch. I opted to buy a pre-made kit to speed things up a bit.
Home Depot, here we come!
With the gutter design “flushed” out and some solid IBC tote stand plans made, I was ready for a local Home Depot trip. Some of the materials I had to order online, as they were not readily available in store.
Rainwater harvesting gutter setup
Once I had all the gutter and first flush parts in hand, I arranged everything on the grass to visually see how all the pieces would come together:
See the long piece of “first flush collection tube” in the picture above? That’s the temporary holding area for the first rainfall flush of the roof. Not seen in the picture is a floating ball that goes inside the tube. As the tube fills with water, the ball rises until it hits a PVC Tee section. The Tee has a small insert that prevents the ball from floating away. Instead, the ball rises and seals the entrance to the first flush collection tube, diverting the water into the other part of the Tee (leading to the IBC tote water storage tank).
Saving money by mixing in smaller sized PVC piping
Also, notice in the gutter setup picture above that I switch from using 3” PVC pipe to smaller 1.5” PVC pipe when leading out to the IBC tote rain storage tank. The only reason I did this was because I already had a long piece of 1.5” PVC pipe in the garage from a previous project. So I took the opportunity to save some money and use that pipe. I just had to purchase a 3” to 1.5” reducer to adapt the two different sized pipes, which was a whole lot cheaper than buying more lengths of 3” PVC piping.
Installing the gutters and downspout
Now it was time to mount the gutters. I used AmeriMax 5” vinyl gutters and their various interconnecting parts to get the job done. It was pretty straight forward. There are tons of tutorials online on mounting gutters, so I won’t bore you with the details. Just make sure the gutters are mounted on a slight slope (about ⅛” drop per every 10 feet of gutter) so standing water drains in the desired direction.
Notice the downspout drop outlet in the picture above. That’s where the water will escape the gutters and enter the rain harvesting system. Gutter sections to the left and right of the drop outlet both slope down slightly towards the outlet.
Mounting the downspout rain collector
Next up was the downspout rain collector. This was also a kit that I purchased online, called the Leaf Eater. It comes with a sloped screen that’s supposed to keep leaves and other larger debris out of the rain harvesting setup. It also adapts the gutter system to standard PVC pipes that comprises the rest of the design.
The Leaf Eater is technically supposed to attach directly to the roofing fascia (the wood trim along the edge of the roof), but there wasn’t enough room for me to do this. So I drilled two small mounting holes into the drop outlet and bolted on the Leaf Eater. The drop outlet was screwed directly in the fascia, so I wasn’t concerned about the Leaf Eater putting too much stress on the gutter system.
Attaching PVC piping and connectors to complete the first flush system
Next I attached some 3” diameter PVC pipes, elbow and a Tee. The PVC tee actually came with the first flush kit.
I secured the tubing to the wall with a metal pipe strap (also came with the kit). I had to bust out the old hammer drill to put some screws into that concrete wall.
Next I attached a 5 foot section of 3″ PVC piping to serve as the first flush collection tube. At the bottom of the tube I inserted the first flush flotation ball (that floats up to divert the rainwater into the IBC tote), and then the slow drain cap.
I was concerned about the weight of the water sitting in the first flush collection tube. So for extra support, I added a piece of metal pipe hanging strap to the Tee section.
The first flush kit also came with some special inserts for the slow drain cap to adjust how fast the tube drained.
Tip: Only use PVC cement where absolutely necessary
As a side note, I was able to dry fit most of the PVC parts together without glue. Dry fitting meant I could swap out PVC parts when necessary to relocate the unit or repair damaged sections. The only parts that needed PVC cement were the first collection tube inserting into the Tee at the top, and that same collection tube inserting into the slow drain cap at the bottom. PVC cement was required at these two junctions, or else the weight of the water would cause the parts to come loose.
Building a strong wooden stand for the IBC tote
Now onto the IBC tote wooden stand. Using my miter saw, I made all the pressure treated wood pieces necessary for the build, cut to lengths dictated by my TinkerCAD design.
All these pieces would come together to form 4 separate segments of the wooden stand. Two segment pairs would contain three 4×4 legs each, while the other two segment pairs joined the leg segments together.
Deck screws and pocket holes go hand in hand
For joining the wood pieces, I used a combination of 3” deck screws and pocket holes (via my Kreg pocket hole jig).
Ratchet straps sure come in handy for large woodworking projects
When fastening the last segment of the wooden stand, there was a ¼” gap that I couldn’t pull close with my body strength. I also didn’t have a long enough bar clamp to help either. So here’s a cool little trick that’s helped me in similar situations in the past. I pulled out a ratchet strap from the garage , and kept tightening it around the stand legs until the gap was closed. Then I attached the final screws to lock the stand segments into place.
Finally the IBC tote wooden stand was done. Eileen and I both jumped around on top the stand to confirm its sturdiness. It felt solid like a rock. We then lifted the IBC tote on top and stepped back to admire our handiwork.
Prepping the IBC tote for Harvesting Rainwater
With the gutter and first flush system completed, and the IBC tote stand done, it was time to prep the IBC tote itself for storing rainwater. This meant adapting it to collect rainwater from the gutter, adding an overflow pipe for excess rainwater, and strapping it securely to the wooden stand
Constructing an adapter for filling the IBC tote with rainwater
Next on the list was to construct a snug fitting entry point into the IBC tote for harvested rainwater to enter. The most obvious location was a red cap at the top of the IBC tote. I wanted to run a piece of 1.5” PVC pipe through the center of the cap, but have the pipe attached very firmly to reduce the chances of contaminants entering through any gaps.
To make the PVC pipe pass through the cap very snugly, I took a piece of flexible PVC coupling, cut it in half and used each half to secure the pipe to the red IBC tote cap. If you’re not familiar with flexible PVC couplings, they are almost rubber like PVC connectors that you can join two PVC pipes with, but allow for a bit of flexibility (unlike solid couplings that make very rigid pipe joins). Each end of the flexible couplings have a ring clamp to lock on tightly to the pipe.
After a hole is drilled through the center of the red cap, the PVC pipe is inserted and secured in place on both sides of the cap with each half of the flexible PVC coupling.
Adding an overflow pipe
I was really happy with this cap to PVC pipe adapter. It felt very solid. Next up was to attach an overflow pipe on the side of the IBC tote. The overflow pipe would allow excess water in the tank to drain out. To attach the overflow pipe, I planned on using the same method as the red cap adapter (with a flexible PVC coupling cut in half to secure the pipe on both ends of the IBC tote wall).
Now one may wonder how I intend on attaching a rubber coupling on the inside wall of the IBC tote. I mean, it’s not very easy access in there, with the red cap port at the top being the only entry point. I thought about this for a bit and came up with a clever solution.
First I drilled a hole (using my hole saw drill attachment) into the wall of the IBC tote where I wanted the overflow pipe to be attached. Then I inserted a really long section of 1.5” PVC pipe through this hole.
Then I guided the inside end of the pipe towards the opening at the top of the IBC tote. Working very carefully through that top opening, I was able to attach the flexible PVC coupling to the pipe. Slow and steady got the job done, because I was worried about dropping the PVC coupling in the IBC tote. It would have been a pain to get it out if it had dropped.
Now, I simply had to pull the overflow pipe all the way out (at least until the inside coupling hit the wall of the IBC tote). Then I attached the outside coupling to the pipe and trimmed the pipe to a shorter length. I would later attach a PVC elbow connector to the end of the overflow pipe to guide the water downwards, as well as a screen to keep bugs out.
Strapping the IBC tote down to the wooden stand
Another thing to take care of was strapping the IBC tote to the wooden stand. An empty IBC tote is not that heavy (around 100 pounds or so). Large gusts of wind may blow an empty tank off the stand. So I secured the IBC tote to the wooden stand with eight strips of pipe hanger (the same hanger strip that I used for additional support strapping the first flush collection tube to the wall). I used 2 strips per each side of the IBC tote.
Getting the IBC tote rainfall storage ready for final hookup
Very close to being done now. I positioned the IBC tote and wooden stand in its designated location, aligned the first flush system so final piping could be done soon.
I love polyolefin deck blocks
Notice those big black bases underneath each leg? They’re heavy duty polyolefin deck blocks. These lightweight blocks can support 1800 pounds each, and accept both 4×4 and 6×6 posts. The reason I used these deck blocks was to help spread out the weight of a full IBC tote. Without them, there’s a good chance that the 4×4 legs would start sinking into the ground over time (from the weight of all the water). They are also pretty cheap, about $10 a block
Now for the moment we’ve all been waiting for – the final hookup to the gutter system!
Making the final connections to the gutter system
It was time to connect the IBC tote to the gutter system. The IBC tote cap-to-PVC adapter with 1.5″ PVC pipe would run up a few inches, then make a 90 degree bend and run straight to the PVC Tee on the first flush system.
Notice in the picture above that I used a flexible PVC elbow to make the 90 degree bend down towards the cap. I wanted there to be a little flexibility if the IBC tote shifted slightly over time, and not put stress on the gutter system hookup.
Using some paint filter mesh to keep out insects
Also, right below the flexible PVC elbow (from the picture above) is a little “skirt” sticking out. That’s some paint filter mesh that I wedged between the PVC pipe and elbow. It serves as a fine filter to further block more contaminants from entering the tank. Insect screen would work just as well. I also used more of the paint filter mesh for the overflow pipe.
We’re hooked up and ready to harvest rainwater
The IBC tote rainwater harvester was finally hooked up to the gutter system. If it started raining right now, it would start filling up the tank.
Keep algae out by covering your IBC tote to block sunlight
There’s a final step to IBC tote rainwater storage that’s very important if you want to maintain clean water. Over time, sunlight will cause algae to start growing in the water. To prevent this, you can cover the entire tote with a dark waterproof fabric. I’ve seen fellow gardeners just wrap their IBC tote in a dark colored tarp. This works great.
I personally opted to buy an IBC tote wrap online (sized for 275 gallon tanks) for a more professional look (and easy access to various parts of the system). The cover I purchased came with a zipper so I can quickly check the IBC tote water level, as well as a velcro flap for the top cap. The cover also straps onto the IBC tote at the bottom (via sturdy snap-on clips), so wind won’t blow it off. I did have to cut a small hole for the overflow pipe though.
Rain, rain, come again! I’m ready for you
So now I have a fully functional IBC tote rainwater harvester setup in my backyard! I attached a garden hose adapter to the bottom IBC tote nozzle to make it compatible with my irrigation system. When I have some extra time, I plan to paint the wooden stand with a waterproof stain to protect it more from the elements. The IBC tote is not yet hooked up to my irrigation system for watering my plants though. For that, I’m currently working on an addendum to this project – converting this IBC tote into a SMART rainwater irrigation system. More on that later when that project is completed.
After a few heavy rainfalls, the IBC tote is completely full of water. I’m very happy with the final results. It was a really fun project to work on, and looks very professional. Estimated building costs were around $500. The project could be done over a very busy weekend, but I took my time and stretched it out over the course of a week.