| Capacity | 500 US gallons / 1,893 liters / 66.8 cubic feet |
| Weight Empty | 80–120 lbs (poly) · 150–200 lbs (fiberglass) · 250–400 lbs (steel) |
| Weight Full | ~4,173 lbs water · ~4,250–4,290 lbs total loaded (poly) |
| Typical Dimensions (Vertical) | ~48" diameter × 56" tall (Norwesco) |
| Typical Dimensions (Horizontal) | ~48" diameter × 86" long |
| Typical Price Range | $350–$900 (poly) · $800–$1,500 (fiberglass) · $500–$1,200 (steel) |
| Common Uses | Farm water storage, fire suppression, pressure washing buffer, mobile detailing, livestock, emergency backup |
| Delivery Note | Most retailers ship via freight — a loading dock or forklift may be needed for large poly tanks |
Who Needs a 500 Gallon Water Tank?
At 500 gallons, you're entering working-farm and commercial-contractor territory. This isn't a tank you keep in a garage corner — it needs a dedicated pad, and at over 4,000 lbs when full, it isn't going anywhere without significant effort. That permanence is exactly what most buyers at this size want.
- Farm and agricultural use: The most common size for small farms. 500 gallons supports livestock watering for medium herds, irrigation buffer for market gardens, or chemical mixing for crop applications.
- Fire suppression: A 500-gallon tank is the minimum practical size for rural fire suppression setups where municipal water isn't available. Many rural fire departments require at least this capacity for permit approval on remote properties.
- Pressure washing contractors: A 500-gallon tank on a trailer provides a full day of commercial pressure washing without needing a water hookup. Essential for parking lots, driveways, and fleet washing.
- Mobile auto detailing at scale: Large detailing operations or fleet service use 500-gallon tanks on enclosed trailers. Supports multiple washes per tank fill.
- Emergency water backup: For households serious about resilience, 500 gallons provides 125+ days of survival-level water for one person. At realistic usage (3 gal/day), it covers a family of four for over 40 days.
- Construction site water: Concrete mixing, dust suppression, equipment washing, and worker supply during off-grid construction projects.
Dimensions by Style
| Style | Diameter / Width | Height / Length | Footprint | Typical Brand |
|---|---|---|---|---|
| Vertical Round | 48" | 56" | ~12.6 sq ft | Norwesco, Snyder |
| Horizontal Transport | 48" dia | 86" long | ~23.8 sq ft | Norwesco, Poly-Mart |
| Elliptical Transport | 48"W × 34"H | 88" long | ~29.3 sq ft | Norwesco (low-profile) |
| Corrugated Steel (Round) | Varies | Varies | Varies | Tank Depot, Bushman |
| Dimensions vary by manufacturer. Confirm with spec sheet before ordering. Freight delivery dimensions matter for access. | ||||
Material Options
Polyethylene (HDPE) — Most Common
The dominant choice at 500 gallons. Rotationally molded HDPE tanks from Norwesco and Snyder are durable, lightweight relative to their capacity, and available in configurations from standard vertical to trailer-ready horizontal transport tanks.
- Lightweight vs. steel (80–120 lbs empty)
- Seamless, no welds to crack
- FDA-rated for potable water
- Best value at this size
- Wide variety of configurations
- UV degradation over decades without shade
- Less impact-resistant than steel in collision scenarios
- Not for fuels or aggressive chemicals
Corrugated Steel
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Fiberglass
Fiberglass 500-gallon tanks are used in agricultural chemical storage, aquaculture, and situations where the stored liquid would react with poly. They're heavier and more expensive than poly ($800–$1,500) but offer superior chemical resistance and a smooth interior that's easy to inspect and clean. For potable water storage, poly is still the better value.
Top 500 Gallon Water Tank Picks (2025)
Accessories You'll Need
- Pump: A 1 HP or larger electric transfer pump is standard for 500-gallon systems. For mobile use, a high-flow 12V pump (like a Flojet or SHURflo Extreme) works well. Budget $80–$400 depending on flow rate requirements.
- 2" Plumbing Fittings: Most 500-gallon tanks use 2" NPT outlets. You'll need a ball valve, union, and appropriate hose or pipe fittings. Brass or poly fittings — avoid iron.
- Concrete Pad: Strongly recommended for permanent installations. A 6"–8" reinforced concrete pad at least 6'×6' is appropriate for a 500-gallon tank. On soil, the load will cause settling over time.
- Overflow Fitting: Install an overflow outlet at the maximum fill line to prevent overfill damage to the lid and fittings.
- Level Gauge or Sight Glass: A tank this size is difficult to visually assess. An external sight gauge or float-based level indicator is worth the $20–$60 investment.
- Tank Heater (cold climates): If storing water in a region with hard freezes, a tank heater or insulated enclosure prevents ice damage. Water expands 9% when freezing — that force will crack any tank.
Where to Buy a 500 Gallon Water Tank
| Retailer | Typical Price | Shipping | Notes |
|---|---|---|---|
| Tank Depot | $399–$649 | Freight delivery | Best selection nationwide; some local pickup options |
| Amazon | $420–$700 | Freight or LTL | Check for Norwesco or Poly-Mart sold by established sellers |
| Tractor Supply | $449–$599 | In-store only | Carry Norwesco; limited to vertical models; in-store pick up only |
| Northern Tool | $420–$620 | Freight or store pickup | Good alternative; carry Poly-Mart and similar brands |
| Local Farm Supply | Varies | Pickup only | Often cheapest; call ahead to confirm stock and brand |
Installation Considerations
A 500-gallon tank demands proper site preparation. Cut corners here and you'll deal with settling, overflow events, or access problems for the life of the tank.
- Concrete pad: The gold standard. A 6" reinforced concrete pad rated for 5,000 lbs distributes the weight properly and keeps the tank level permanently.
- Gravel bed alternative: 4"–6" of compacted gravel is acceptable for rural and agricultural use. Level it carefully — a tilted 500-gallon tank becomes a problem when nearly full.
- Freeze protection: In USDA hardiness zones 5 and below (below 0°F), a water-filled poly tank can crack. Bury it below the frost line, use a tank heater, or drain it in winter.
- Permitting: Most 500-gallon tanks don't require permits for agricultural or rural use. For fire suppression systems connected to a structure, check with your local fire authority.
- Access for fill truck: If filling via a water delivery truck, ensure a minimum 12-foot-wide access path and enough clearance for the truck to park near the fill port.
Frequently Asked Questions
500 gallons of water weighs 4,172.5 pounds (8.345 lbs × 500). A poly tank adds 80–120 lbs empty, so total loaded weight is approximately 4,250–4,290 lbs — just over 2 tons. Plan your foundation and access accordingly.
Norwesco's standard vertical 500-gallon poly tank measures approximately 48 inches in diameter and 56 inches tall. Horizontal transport models run approximately 48" diameter × 86" long. Exact dimensions vary — confirm with the manufacturer spec sheet, especially if planning around a tight space or trailer fit.
Standard poly vertical tanks run $350–$530 at most retailers. Horizontal transport tanks (better for trailers) are $450–$650. Corrugated steel runs $580–$850. Fiberglass starts at $800 and up. Shipping adds $50–$200 for freight delivery. Total delivered cost: typically $450–$700 for a standard poly tank.
Yes — 500 gallons is the minimum practical size for rural fire suppression. It's enough water to attack a small structure fire or wildland ember strike while waiting for the fire department. For serious fire protection, most experts recommend 1,000–2,500 gallons. If building toward code, consult your local fire authority — many have minimum capacity requirements for rural property permits.
Yes — horizontal transport tanks are designed specifically for this. Make sure your trailer's GVWR (Gross Vehicle Weight Rating) exceeds the full tank weight. A full 500-gallon tank weighs over 4,200 lbs. Add the trailer weight (typically 500–1,500 lbs), and you need a trailer and hitch rated for 5,000–6,000 lbs minimum. Never exceed your tow vehicle's towing capacity. For commercial transport, a DOT-compliant setup may be required depending on your state.
At FEMA's survival minimum of 1 gallon/person/day: 500 days for one person, 125 days for a family of four. At realistic usage (3 gal/person/day including cooking and basic hygiene): ~42 days for a family of four. For full household use including showers and laundry (75–100 gal/person/day): 1.25–1.67 days for a family of four. For drinking and cooking only (0.5 gal/person/day): over a year for a single person.