AutoPot FlexiTank Reservoirs – 105 Gallon

The AutoPot FlexiTank 105 Gallon is a collapsible, tool-free water storage reservoir designed for hydroponic and irrigation systems where space, storage, or transport is a constraint. It ships flat in a compact box, assembles in minutes without tools, and holds 105 gallons of nutrient solution or water when filled. Unlike rigid barrels and tanks, the FlexiTank can be folded away when not in use, making it practical for seasonal growers and growers with limited room between runs.

AutoPot FlexiTank 105 Gallon Specifications

All dimensions sourced from manufacturer documentation. Boxed dimensions reflect flat-packed shipping state; filled dimensions reflect the tank when at capacity.

Specification	Value
Capacity	105 Gallons
Box Size (L x W x H)	44 x 5 x 7 inches
Boxed Weight	9 lbs
Diameter When Full	26.8 inches
Height When Full	43.7 inches
Brand	Autopot Watering Systems USA
Assembly	Tool-free, no hardware required
Storage	Collapsible — folds flat when empty

Why Choose the AutoPot FlexiTank 105 Gallon

The FlexiTank addresses a practical problem that rigid reservoirs cannot: space. A 105-gallon hard tank takes up significant floor space year-round, even when empty. The FlexiTank folds flat and fits in its 44 x 5 x 7-inch shipping box when not in use, freeing grow room floor space between crops or during facility reconfiguration.

• No tools required for assembly. The FlexiTank goes from box to functional reservoir in minutes. There are no bolts, clamps, or fittings to assemble. For growers who rotate reservoirs or set up temporary grow spaces, this eliminates a common friction point.
• Compact shipping and storage footprint. At 9 lbs boxed and shipping dimensions of 44 x 5 x 7 inches, the FlexiTank is substantially lighter and easier to transport and store than comparable rigid 105-gallon tanks, which typically weigh 20–40 lbs and occupy significant cubic volume even when empty.
• Fits where standard reservoirs cannot. The collapsible construction means the FlexiTank can be carried through standard doorways and into grow spaces that would be difficult to access with a large rigid tank. Once inside, it unfolds and fills in place.
• Adaptable to irregular spaces. Unlike rigid cylindrical or rectangular tanks, the FlexiTank’s flexible walls allow it to conform somewhat to the available footprint, making it easier to position in corners or against walls.
• Reusable and storable between grows. After a run, the FlexiTank can be emptied, cleaned, dried, and folded back into its compact stored state. Growers who take breaks between crops or run seasonal operations find this more practical than leaving a large empty tank sitting in their space.

Best Uses for the AutoPot FlexiTank 105 Gallon

The 105-gallon FlexiTank suits a specific range of grow sizes and setups. It is most useful where a large nutrient reservoir is needed but permanent installation of a rigid tank is impractical.

• AutoPot gravity-fed systems with multiple pots. AutoPot systems are gravity-fed from a central reservoir with no pumps or timers. A 105-gallon reservoir supports medium-to-large AutoPot arrays — typically 16 to 30+ pots depending on plant water consumption — without requiring frequent refills. The FlexiTank connects to AutoPot systems via standard fittings and operates at the same floor-level gravity head as other AutoPot reservoirs.
• Grow rooms and tents with limited access. Getting a large rigid tank into a grow tent or through a narrow grow room doorway is often difficult. The FlexiTank can be carried in flat, positioned, and then unfolded and filled in place — useful for spaces where a 27-inch-diameter filled tank would be hard to maneuver through doorways.
• Seasonal and rotating grow operations. Growers who run discrete crop cycles with gaps between them can fold the FlexiTank flat and store it during off periods. This is practical in shared or multi-use spaces where a 105-gallon tank sitting idle between runs would be an obstacle.
• Backup or supplemental reservoir capacity. The FlexiTank can serve as a supplemental reservoir to extend the total water storage capacity of an existing system. Its collapsible storage means it does not take up space when the supplemental capacity is not needed.
• Water storage where rigid tanks cannot fit. Narrow utility corridors, basement grow rooms with low clearance stairwells, and other constrained spaces that make rigid tank delivery impractical are suitable candidates for the FlexiTank.

AutoPot FlexiTank 105 Gallon vs Standard Rigid Reservoirs

Growers evaluating the FlexiTank 105 Gallon typically compare it against traditional rigid poly tanks or heavy-duty storage bins of similar volume. The comparison comes down to a tradeoff between structural rigidity and space/transport flexibility.

A rigid 105-gallon poly tank is a fixed cylinder or rectangular box. It does not compress, fold, or reduce in footprint when empty. Carrying one into a grow room or tent typically requires maneuvering a large, awkward object through doorways. When the tank is not in use between grows, it occupies the same floor space it does when full.

The FlexiTank ships at 44 x 5 x 7 inches and weighs 9 lbs — a substantially smaller shipping profile than most rigid 105-gallon tanks. It can be carried flat, positioned in the space where it will be used, and filled in place. After a grow cycle, it can be emptied and returned to that same compact footprint for storage.

The tradeoff is that flexible tanks are generally less structurally robust than rigid poly tanks over long continuous use and may be more susceptible to puncture from sharp objects nearby. Growers who keep a reservoir filled and in the same location indefinitely may find a rigid tank more durable for permanent installation. The FlexiTank is better suited for growers who value the setup, transport, and storage flexibility it provides. Those interested in other AutoPot reservoir options can also review the AutoPot 12.4 Gallon Hard Tank for smaller, fixed-volume permanent installations.

Compatibility

The AutoPot FlexiTank 105 Gallon is designed for use with AutoPot gravity-fed watering systems and can function as the central reservoir in an AutoPot array. It works with the standard AutoPot feed line and AquaValve system.

Because AutoPot systems are gravity-fed rather than pump-driven, the reservoir needs to be positioned at the same level or slightly above the pots. The FlexiTank’s filled dimensions — 26.8 inches in diameter and 43.7 inches tall — should be factored into grow room layout planning. It requires a stable, level surface capable of supporting its filled weight. Water weighs approximately 8.34 lbs per gallon, so a full 105-gallon FlexiTank will hold roughly 875 lbs of water; the surface and floor beneath it must be rated to support this load.

If you are running an AutoPot system that also uses an airdome for root zone oxygenation, a compatible air pump can be connected to supply the airdome while the FlexiTank serves as the reservoir. AutoPot airdome kits connect to the reservoir via standard barbed fittings.

The FlexiTank is compatible with nutrient solutions at standard hydroponic concentrations. Growers using reverse osmosis water as a base should ensure their RO system output is sufficient to fill and maintain a 105-gallon reservoir; a 75 GPD RO system can fill this reservoir over approximately 1.4 days of continuous output.

Usage Guidelines

The FlexiTank requires a stable, flat, level surface. Do not place on surfaces with sharp projections that could puncture the tank material. Rough concrete floors benefit from a protective mat beneath the tank.

When using with an AutoPot gravity-fed system, the reservoir and pots should be on the same level surface. AutoPot AquaValves are gravity-actuated and rely on a consistent water head to function correctly. Do not elevate the reservoir significantly above pot level unless the AutoPot system is specifically configured for elevated reservoir use — standard AquaValves are designed for floor-level setups.

Fill rate should be controlled to avoid overfilling. The 105-gallon capacity is the maximum fill volume; leave some headspace if adding nutrients or pH adjustments after initial fill. Monitor water level regularly, particularly in the first few days after setup, to confirm the feed rate from the reservoir matches plant uptake in the AutoPot array.

When emptying for storage, drain completely and rinse the interior with clean water. Allow the tank to dry fully before folding and storing. Folding a damp tank and storing it in an enclosed space can lead to mold or mildew buildup inside the folds.

How to Set Up the AutoPot FlexiTank 105 Gallon

1. Select and prepare the installation location. Choose a flat, level surface capable of supporting approximately 875 lbs of water (plus the weight of the tank itself and any fittings). Clear any sharp debris from the floor area. A rubber mat or protective layer between the tank and floor is recommended on rough or abrasive surfaces.
2. Unpack and unfold the FlexiTank. Remove the FlexiTank from its shipping box. Unfold the tank fully in the location where it will be used. No tools are required. Ensure the tank is fully unfolded and the base is sitting flat before proceeding.
3. Connect AutoPot feed line fittings. Attach the AutoPot supply line fitting to the reservoir outlet at the base of the FlexiTank. Hand-tighten fittings and check for leaks before filling. Do not over-tighten plastic fittings.
4. Fill with water and nutrient solution. Begin filling the reservoir with water. If mixing nutrients, add the measured nutrient concentrate to the reservoir water and mix thoroughly. Check and adjust pH to the target range for your crop and growing medium. Verify EC is within the target range using a calibrated EC meter.
5. Open the feed line to the AutoPot system. Once the reservoir is filled to the desired level and nutrient solution is verified, open the feed line to allow water to flow to the AquaValves. Confirm that all AquaValves are functioning and that water is reaching each pot as expected.
6. Monitor for the first 24–48 hours. Check for any leaks at fittings and confirm the reservoir level is dropping at a rate consistent with plant water consumption. Refill and top up nutrient solution as needed during the grow cycle.

Sources & Further Reading