8 Kits for Connecting Rainwater Harvesting Barrels

A single heavy downpour can fill a standard 50-gallon rain barrel in a matter of minutes, leaving valuable irrigation water to overflow and go to waste. For a hobby farm or homestead, scaling up your water storage capacity is the smartest way to safeguard your crops through dry summer stretches. Linking multiple barrels together creates a highly efficient, modular gravity-fed system that maximizes every drop of run-off from your barn or coop roof.

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Why You Should Link Multiple Rain Barrels

A single rain barrel is rarely enough to sustain a productive vegetable patch or a small flock of poultry through a dry spell. During a heavy storm, gutters channel hundreds of gallons of water off even a modest roof. By linking multiple barrels, you capture this surplus instead of letting it saturate your foundation or wash away topsoil.

This modular approach is far more practical than investing in a massive, expensive commercial cistern. Standard plastic drums are cheap, highly portable, and easy to source. Linking them allows you to expand your storage capacity incrementally as your growing operation scales up, without requiring heavy machinery for installation.

Furthermore, a multi-barrel setup offers built-in redundancy and flexibility. If one barrel develops a leak or needs cleaning, you can isolate it from the system without losing your entire water reserve. You can also distribute the weight of the water across a larger footprint, which is crucial when setting up storage on temporary platforms or sloped homestead terrain.

How to Choose the Right Connector Kit

Selecting the right connection system depends on how you plan to draw water and where your barrels are positioned. The two primary methods are top-linking and bottom-linking. Top-linking acts as an overflow system where the first barrel fills completely before spilling into the next, while bottom-linking uses gravity to keep the water levels equal across all connected tanks.

Pay close attention to the hose diameter and material quality. A narrow hose will restrict water flow, causing the primary barrel to back up and overflow during intense downpours. Look for heavy-duty, UV-resistant materials like EPDM rubber or reinforced polyethylene that can withstand freezing temperatures and intense summer sun without cracking.

• Hose Diameter: 1-inch or larger is ideal for rapid equalization during heavy storms.
• Fitting Material: Brass or heavy-duty polypropylene resists stripping and corrosion.
• Gasket Quality: Deep EPDM rubber gaskets are essential for preventing slow, frustrating leaks.

Finally, consider the tools required for installation. Some kits come complete with the exact drill bits and hole saws needed to pierce plastic drums, while others assume you already have these in your workshop. Matching the kit to your current tool inventory will save you an extra trip to the hardware store.

Linking Kit – EarthMinded 31-Inch Link Kit

The EarthMinded 31-Inch Link Kit is designed to connect two barrels positioned close to one another, typically on the same level. This kit functions as a top-to-top overflow connector, allowing the first barrel to fill to capacity before redirecting excess water into the secondary tank. It provides a simple, reliable way to double your storage without complicated plumbing.

This specific kit excels because it includes a 31-inch corrugated hose that is highly flexible, allowing you to position barrels around corners or on slightly uneven platforms. The package comes complete with a hole saw, rubber seals, and screws, ensuring you have the exact dimensions needed for a watertight fit. The rubber seals use a push-fit design that grips the barrel wall tightly without requiring interior nuts.

• Hose Length: 31 inches
• Connection Type: Push-fit rubber seals
• Best For: Side-by-side barrels on level ground

Before purchasing, note that the corrugated hose can collect small amounts of sediment in its ridges over time. This kit is ideal for growers who want a quick, tool-inclusive setup for two standard plastic drums. It is not suitable for high-pressure bottom-linking where constant water weight presses against the seals.

Diverter Kit – Oatey Mystic Collection System

The Oatey Mystic Collection System is a specialized diverter kit that channels rainwater directly from your downspout into your primary collection barrel. It plays a critical role in preventing debris like leaves and twigs from entering your storage system in the first place. Once the connected barrel is full, the diverter naturally redirects excess water back down the downspout to protect your foundation.

This unit stands out due to its heavy-duty thermoplastic construction, which fits standard 2×3-inch residential downspouts. Unlike flimsy plastic inserts, the Mystic uses a deep reservoir cup to capture water clinging to the inside walls of the downspout, maximizing collection efficiency. The included high-flow outlet hose connects directly to your lead barrel with minimal flow restriction.

• Compatible Downspout Size: 2×3 inches
• Material: UV-resistant thermoplastic
• Key Feature: Automatic overflow bypass

Installation requires cutting a small section out of your metal or vinyl downspout, which requires a steady hand and a hacksaw. This kit is perfect for hobby farmers setting up their very first collection point on a barn or shed gutter. It is not suitable for round downspouts or larger 3×4-inch commercial gutter systems.

Bulkhead Fitting – Rain Brothers 1-Inch Fitting

When building a custom multi-barrel manifold, a high-quality bulkhead fitting is the most critical component. The Rain Brothers 1-Inch Fitting creates a permanent, watertight threaded port through the curved wall of any plastic drum. This allows you to connect standard plumbing pipes, valves, or high-flow hoses directly to the bottom of your tanks.

The defining feature of this fitting is its reverse-thread design, which prevents the bulkhead from spinning or loosening when you screw in a hose or spigot from the outside. It features a thick, heavy-duty EPDM gasket that compresses perfectly against curved plastic surfaces to eliminate slow drips. The robust polypropylene body resists cracking even when subjected to seasonal temperature swings.

• Thread Size: 1-inch NPT female
• Required Hole Size: 1.75 inches
• Gasket Material: Heavy-duty EPDM rubber

Because this fitting requires access to the inside of the barrel to tighten the nut, it is best used on open-top drums or barrels with removable lids. It is the ultimate choice for DIY enthusiasts building high-capacity, bottom-linked irrigation systems. It is not recommended for sealed-top drums unless you have specialized long-reach tools.

Connection Hose – RTS Home Decors Connector Kit

The RTS Home Decors Connector Kit is built specifically for linking flat-backed or decorative barrels that sit flush against a wall. Its primary role is to provide a low-profile, highly durable bridge between two adjacent tanks. This keeps your footprint compact while ensuring water equalizes quickly between the units.

This kit features a short, reinforced braided hose that resists kinking and crushing under pressure. The brass fittings offer excellent thread durability, reducing the risk of cross-threading during seasonal assembly and disassembly. It provides a clean, professional look that blends well into backyard garden spaces or highly visible farm stands.

• Hose Material: Reinforced braided vinyl
• Fitting Material: Solid brass
• Connection Distance: Under 20 inches

The short length of this hose leaves very little room for error when positioning your barrels; they must be placed almost touching. This kit is perfect for growers using matching, manufactured rain barrels on flat concrete pads. It is not suitable for connecting rough, mismatched utility drums spaced far apart.

Daisy Chain Kit – RainReserve Daisy Chain Kit

If you need to link three or more barrels in a continuous series, the RainReserve Daisy Chain Kit is the most efficient option on the market. This kit allows you to construct a high-capacity daisy chain from the top ports of your barrels. This configuration ensures that each barrel fills completely before the water moves to the next, keeping your primary water reserve concentrated.

The strength of this kit lies in its high-flow, self-sealing threaded fittings that minimize the risk of leaks at the connection points. The tubing is thick-walled and opaque, which prevents sunlight penetration and discourages algae growth inside the lines. It also includes all necessary drill bits, making the installation process straightforward even for beginners.

• Max Barrels Supported: Unlimited (modular design)
• Tubing Type: Opaque, algae-resistant vinyl
• Included Tools: Spade drill bit

Keep in mind that top-linking multiple barrels means you will need a spigot on each barrel to access all the water, or a separate bottom manifold. This kit is ideal for scaling up storage along a long barn wall where space allows for a linear run of tanks. It is not ideal for tight, clustered layouts.

Expansion Kit – Algreen Rain Barrel Connector Kit

The Algreen Rain Barrel Connector Kit is designed for rapid, tool-free expansion of existing Algreen barrels or generic flat-back setups. Its role is to simplify the linking process by utilizing pre-existing threaded ports or easily drilled entry points. It offers a highly flexible connection that tolerates slight shifting of the barrels over time.

This kit stands out because of its kink-free corrugated tubing and simple dual-threaded connectors. The plastic threads are designed to seal tightly with minimal hand-tightening, reducing the risk of damaging the barrel’s built-in ports. The neutral color scheme helps the tubing blend into the shadows behind your barrels, keeping the setup looking tidy.

• Hose Type: Kink-free corrugated plastic
• Thread Type: Standard coarse thread
• Flexibility: High

Because the fittings are made of lightweight plastic, they can become brittle if exposed to extreme sub-zero temperatures while filled with water. This kit is best suited for seasonal growers who dismantle their systems for winter storage. It is not recommended for heavy-duty, year-round agricultural use in freezing climates.

Linking Hose – Graf Rain Barrel Connection Kit

For high-precipitation regions where standard garden hoses simply cannot handle the volume of water coming off a roof, the Graf Rain Barrel Connection Kit is the heavy-duty answer. This kit uses a wide-diameter hose to facilitate rapid water transfer between barrels. This prevents the primary barrel from backing up and spilling over the top during torrential downpours.

The standout feature is the 1.25-inch internal diameter hose, which offers significantly higher flow rates than standard 3/4-inch garden hose kits. The fittings are constructed from thick, impact-resistant polyethylene designed to withstand rough farm environments. The kit includes a specialized crown drill bit to ensure a perfect, burr-free hole in your barrels.

• Hose Diameter: 1.25 inches
• Material: Impact-resistant polyethylene
• Flow Rate: High-volume capacity

The larger hose diameter requires drilling a substantial hole in your barrels, meaning you must be precise with your measurements before cutting. This kit is the perfect choice for growers in tropical or high-rainfall areas who rely on fast-filling systems. It is not necessary for arid climates with gentle, slow-moving rain patterns.

Spigot Link – Good Ideas Rain Wizard Connector Kit

The Good Ideas Rain Wizard Connector Kit is designed to connect two barrels via their bottom brass spigots. This bottom-linking configuration allows the water levels in both barrels to equalize automatically as they fill and drain. This means you only need to connect your garden hose to a single spigot to access the water stored in both tanks.

This kit is highly regarded for its solid brass connector fittings and heavy-duty rubber hose. The brass construction ensures that the threads will not strip or degrade under the constant pressure of holding back dozens of gallons of water. The hose is highly durable, resisting UV damage and kinking even when positioned close to the ground.

• Connection Point: Bottom spigots
• Fitting Material: Heavy-duty brass
• Equalization Style: Continuous bottom-flow

To use this kit effectively, both barrels must be placed on the exact same level; otherwise, the lower barrel will overflow. This kit is ideal for small-scale growers who want a convenient, single-point water outlet for their gravity-fed irrigation lines. It is not suitable for setups placed on uneven, unpaved ground.

Step-by-Step Tips for Linking Your Tanks

Before drilling any holes, you must prepare a stable, level foundation for your barrels. Water is incredibly heavy, weighing approximately 8.34 pounds per gallon; a linked pair of 55-gallon drums will weigh nearly 1,000 pounds when full. Use compacted gravel, level concrete pavers, or a sturdy wooden platform to prevent the barrels from tipping or shifting, which can tear the connection hoses.

When drilling your entry points, always use the specific hole saw size recommended by your kit manufacturer. Run your drill at a moderate speed to avoid melting the plastic, which creates rough edges that prevent a clean seal. Use a utility knife to deburr the edges of the hole before inserting rubber gaskets or bulkhead fittings.

• Always apply a thin layer of silicone sealant or Teflon tape to threaded fittings to ensure a drip-free seal.
• Position your linking hoses as straight as possible to prevent airlocks from trapping water in one barrel.
• Keep the primary inlet barrel slightly higher than the secondary barrels if you are relying on a top-spill overflow system.

Once connected, perform a dry run by filling the first barrel with a garden hose to check for leaks at the connection points. It is much easier to tighten a bulkhead or adjust a gasket before the entire system is filled with cold, heavy rainwater.

How to Winterize Your Connected Rain Barrels

Leaving water in your linked rain barrels over winter is a recipe for disaster. When water freezes, it expands by about nine percent, which will easily crack plastic drums, split connection hoses, and ruin expensive brass valves. Winterization should be a standard part of your autumn farm maintenance checklist before the first hard freeze arrives.

Begin by completely draining all the connected barrels and disconnecting the linking hoses. Store the hoses, diverters, and brass spigots in a dry shed or workshop to protect the rubber seals from cracking in the cold. If your barrels have bottom drains, leave them open to ensure no condensation or residual rainwater pools inside and freezes.

• Drain: Empty all tanks completely.
• Disconnect: Remove all flexible hoses and store them indoors.
• Divert: Reconnect your downspout bypass to direct winter melt away from your foundation.

If you must store your barrels outdoors, turn them upside down and secure them so they do not blow away in winter storms. Alternatively, cover the top openings with heavy-duty tarps to prevent snow and ice from accumulating inside. Taking these simple steps ensures your harvesting system will be ready to perform when the spring rains arrive.

Linking your rainwater harvesting barrels is a highly practical, cost-effective project that dramatically increases your farm’s water security. By selecting the right connector kit and installing it on a stable, level foundation, you create a resilient irrigation resource that handles heavy summer storms with ease. Protect your investment with proper seasonal maintenance, and your modular watering system will serve your crops and livestock for years to come.