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When your RV's fresh water system needs a reliable, long-lasting tank, the Alpha 18 Gallon RV Fresh Water Tank VR304565WBLANK delivers OEM-grade performance in a uniquely flat, wide-footprint design. At just 6 1/2" deep with a 45" x 30" base, this tank fits where taller tanks simply can't — making it the go-to solution for under-floor RV bays, horse trailers, and marine applications with tight vertical clearance.
Features & Specifications
- Capacity: 18 gallons of potable fresh water storage
- Dimensions: 45" x 30" x 6 1/2" — ultra-low-profile design for tight-clearance installs
- Part Number: VR304565WBLANK
- Material: FDA-approved, food-grade polyethylene — safe for drinking water
- Construction: Seamless one-piece rotational molding — zero seams, zero leak points
- Fittings: Blank tank (no pre-drilled holes) — fully customizable for your plumbing layout
- Finish: Stain, corrosion, and rust resistant — built for years of reliable service
- Weight: 52.86 lbs
- Compatibility: RVs, travel trailers, motorhomes, horse trailers, marine vessels
Why Choose the Alpha VR304565WBLANK?
Most factory-installed RV fresh water tanks are adequate at best. The Alpha 18 gallon RV fresh water tank VR304565WBLANK is engineered to exceed OEM standards — not just meet them. Its seamless rotational-molded construction eliminates the weak points that cause leaks in lesser tanks, while the FDA-approved polyethylene ensures every drop of water stored is safe for drinking.
The blank tank design gives you complete control over your plumbing configuration. Whether you're doing a direct OEM replacement or a custom install, you drill your own fittings exactly where your system requires. No compromises, no adapters.
The low-profile 6 1/2" depth is the standout feature of this Alpha fresh water tank — it slides into under-floor bays and compartments where standard tanks won't fit, making it a favorite for slide-in replacements on older RVs and custom horse trailer builds.
Compare Alpha Fresh Water Tanks
Not sure if the 18-gallon is the right size for your rig? Compare the full Alpha lineup to find your perfect fit:
| Model (Part #) | Capacity | Dimensions (L x W x H) | Best For | View Details |
|---|---|---|---|---|
| VR304565WBLANK ⬅ This Tank | 18 Gallons | 45" x 30" x 6 1/2" | Ultra-low-profile under-floor installs | — |
| 384BLANK | 10 Gallons | 17" x 14" x 9.5" | Small RVs, truck campers, pop-ups | View → |
| 385BLANK | 16 Gallons | 24" x 15.5" x 10.5" | Standard RV replacement, compact bays | View → |
| VR182611WBLANK | 22 Gallons | 26.5" x 18" x 11" | Travel trailers, motorhomes, marine | View → |
| VR17449WBLANK | 26 Gallons | 44" x 17" x 9" | Motorhomes, horse trailers, off-grid | View → |
💡 Tip: When choosing a tank, always measure your available bay space (length, width, AND height clearance) before ordering. The VR304565WBLANK's 6 1/2" height makes it ideal when vertical space is the limiting factor.
Technical Specifications
- Capacity: 18 gallons (68.1 liters)
- Length: 45"
- Width: 30"
- Height: 6 1/2" (6.5")
- Weight (empty): 52.86 lbs
- Part Number: VR304565WBLANK
- Material: FDA-approved food-grade polyethylene
- Manufacturing Method: Rotational molding (seamless one-piece)
- Fittings: None pre-installed (blank tank)
- Color: Natural/White
- Certifications: FDA-approved for potable water storage
- Applications: RV, travel trailer, motorhome, horse trailer, marine vessel
What's Included
- 1x Alpha 18 Gallon Fresh Water Tank (VR304565WBLANK)
- Blank tank — no fittings pre-installed (drill your own to match your plumbing)
- Manufacturer warranty against defects in materials and workmanship
Compatible Models & Related Products
Looking for a different size or a tank with pre-installed fittings? Browse the full Alpha fresh water tank lineup:
- Alpha 10 Gallon RV Fresh Water Tank - 384BLANK — compact option for small rigs
- Alpha 16 Gallon RV Fresh Water Tank - 385BLANK — popular mid-size replacement
- Alpha 22 Gallon RV Fresh Water Tank - VR182611WBLANK — step up in capacity
- Alpha 26 Gallon RV Fresh Water Tank - VR17449WBLANK — wide flat profile, more capacity
Frequently Asked Questions
Is the VR304565WBLANK safe for drinking water storage?
Yes. This tank is made from FDA-approved food-grade polyethylene, making it fully certified for potable (drinking) water storage in RVs, trailers, and marine applications.
Does this tank come with fittings pre-installed?
No — this is a blank tank with no pre-drilled holes or fittings. This gives you full flexibility to drill and install fittings exactly where your plumbing system requires.
How do I install the Alpha VR304565WBLANK in my RV?
Measure your bay opening to confirm the 45" x 30" x 6 1/2" dimensions fit. Drill your inlet, outlet, and vent holes using a hole saw sized for your fittings, install tank fittings with appropriate sealant, and connect to your existing plumbing lines.
What RV brands is this tank compatible with?
This is a universal blank tank compatible with any RV, travel trailer, motorhome, horse trailer, or marine vessel that can accommodate its 45" x 30" x 6 1/2" footprint. Always verify your bay dimensions before ordering.
Why is the VR304565WBLANK so flat compared to other 18-gallon tanks?
The wide 45" x 30" base spreads the 18-gallon capacity across a large, shallow footprint — ideal for under-floor bays with limited vertical clearance. If you have more height available, the 22-gallon VR182611WBLANK may offer a better fit.
Where can I buy an authentic Alpha VR304565WBLANK?
ElkhartRVParts.com is an authorized Alpha Systems dealer. Purchasing here guarantees you receive a genuine OEM-grade part backed by the manufacturer's warranty.
Our AI Live Chat is available 24/7 to help you confirm compatibility, check dimensions, and get your order placed quickly. Don't guess — get the right tank the first time.
| Product type | Fresh Water Tank |
|---|---|
| Capacity | 18 Gallons |
| Dimensions | 45" x 30" x 6 1/2" |
| Material | Polyethylene |
| Construction | Seamless One-Piece Rotational Molded |
| Fda approved | Yes |
| Compatible vehicles | RVHorse TrailerMarine Vessel |
| Model number | VR304565WBLANK |
| Brand | Alpha |
- What material is the alpha 18 gallons fresh water tank made of? The tank is made from high-quality, durable polyethylene that is FDA-approved for safe drinking water storage.
- What are the dimensions of this fresh water tank? The tank measures 45 inches in length, 30 inches in width, and 6 1/2 inches in height.
- Is this water tank suitable for use in rvs and marine vessels? Yes, this tank is ideal for RV enthusiasts, horse trailer owners, and marine adventurers looking for a reliable water storage solution.
- Does the tank have any seams or joints that could leak? No, the tank features a seamless one-piece construction designed for superior strength and leak-proof reliability.
- How does this tank compare to standard factory-installed fresh water tanks? This tank is built tougher, with stain, corrosion, and rust resistance, and is made from premium materials, making it more durable and dependable than many standard factory-installed tanks.
Factory-Fresh OEM Parts — the same brands installed in new RVs straight from Elkhart. Genuine, name-brand components made to order — never generic, never outdated. Sourced directly from the original RV manufacturers for perfect fit and factory-level quality.





