If you’re outfitting a camper, underbody water tanks provide durable, space-saving storage for fresh water, gray water, or waste. This guide highlights practical options for keeping your RV hydrated and self-sufficient, while also noting limits like installation requirements and material compatibility. The top picks mix built-in mounting options, portability, and easy installation to fit a range of camper layouts and travel styles. Ideal buyers include long-term travelers needing large fresh-water capacity, weekend campers seeking quick swap-and-go tanks, and DIY installers prioritizing robust, standardized fittings.
| Product | Capacity | Type | Best For | Notes |
|---|---|---|---|---|
| Ameri-Kart WT-5549 | 36 Gallons | Fresh Water | Full-time RVers needing ample potable water | USA-made, BPA-free, IAPMO compliant |
| Ameri-Kart WT-5450 | 19 Gallons | Fresh Water | Smaller RVs or secondary tank needs | Compact, durable construction |
| STAR BRITE Aqua Tank Flush | 1 Gallon (system cleaner) | Water System Cleaner | Preventive maintenance after storage | Deodorizes entire drinking system |
| Class A Customs UM-3000 | 30 Gallons | Fresh/Gray Water | Under-mount or underbody installation | NSF-approved materials, versatile use |
| SereneLife 75L Portable Tank | 75 Liters / ~20 Gallons | Portable Water Tank | Temporary or portable water supply | Wheels and level gauge for easy mobility |
Camco Rhino 36-Gallon RV Tote Tank
Best for long trips where you need a large, portable waste tote that can be towed or hauled across uneven terrain. The tank weighs 45 lb and measures 24 1/8” L x 14 3/4” W x 44 7/8” H, ensuring substantial capacity without overburdening the vehicle. It includes no-flat wheels for reliable mobility and a built-in gate valve for simple disposal. Suitable for campers with remote dump locations or limited sewer hose reach. Caution: larger size may be heavier to lift and maneuver in tight spaces.
Camco Rhino 28-Gallon Tote Tank
Best for mid-size campers needing a compact yet capable waste tote with stable wheels and a steel tow adapter. Its dimensions are 14 ½” L x 24” W x 44” H and it weighs 43 lb. The design supports towing behind a truck or golf cart, making it convenient for dispersed campsites. Limitation: smaller capacity than the 36-gallon model, so plan for more frequent disposal on longer trips.
Ameri-Kart 36 Gallon Fresh Water Tank WT-5549
Best for RVs requiring a sizable, potable water reservoir made in the USA. This 36-gallon tank is built from BPA-free materials and features two 1.5″ balloon-style threaded female NPT fittings plus two 0.5″ NPT fittings for flexible installation. It is designed to be sanitary and leak-proof, with durability under outdoor use. Choose this if you need substantial onboard water and straightforward fittings; avoid if your space requires under-body clearance lower than standard tanks.
Ameri-Kart 19 Gallon Fresh Water Tank WT-5450
Best for smaller RVs or secondary water storage needs. This 19-gallon tank uses BPA-free plastics, with multiple fitting locations for installation. It provides two 1.5″ NPT and two 0.5″ NPT fittings, offering installation flexibility. It’s a good fit where space is tight or when a lighter, easier-to-manage tank is preferred; avoid if you require a larger freshwater reserve for extended off-grid trips.
STAR BRITE Aqua Water Tank & System Flush
Best for campers who want to maintain fresh-water quality after periods of storage. This product deep-cleans and deodorizes the entire drinking water system, removing scale and sediment that can cause taste and odor issues. It’s a maintenance item rather than a storage tank, but essential for keeping potable water fresh on larger trips. Limitation: does not store water; used for system cleaning only.
Class A Customs UM-3000 Under Mount 30 Gallon Tank
Best for mounting under the vehicle with a robust, flexible design for fresh or gray water. The 30-gallon tank measures 48″ long (excluding fittings) with a height and width that can be rotated or oriented to fit specific underbody spaces. It includes two 1.5″ NPT fittings and two 0.5″ NPT fittings. Best for installers needing an under-mount solution; caution: not designed for potable water use if installed in certain configurations—verify compliance with local codes for your setup.
classAcustoms WT-3161 31 Gallon Black Water Tank
Best for waste-management needs where underbody installation is preferred. This 31-gallon black water tank is designed for waste/gray-water storage only and requires user-determined inlet/vent placement. It uses MDPE resin and standard 3″ outlet piping. It is not rated for fresh water use. Choose this if your system relies on a dedicated waste tank; avoid if you need potable water storage or a ready-to-install, factory-fitted configuration.
Buying Guide: Underbody RV Water Tanks And Portable Options
- Purpose: Decide between fresh water storage, gray water, or waste tanks. Fresh-water tanks prioritize food-grade materials and leak-proof construction; waste tanks emphasize external fittings and venting.
- Capacity vs. Space: larger tanks increase on-board water but require space and weight considerations. Under-mount or tote-style designs fit different RV layouts; measure clearance before purchase.
- Materials And Compliance: Look for BPA-free plastics for potable water and NSF-approved materials for safety. For under-mount tanks, ensure compatibility with your RV’s mounting points and door clearance.
- Fittings And Connections: Check the number and size of fittings (NPT standards like 1.5″ and 0.5″) and whether adapters are needed for your hoses and valves.
- Mobility And Handling: For portable totes, consider wheels, handles, and tow adapters. Removable or lockable wheels improve stability on uneven surfaces.
- Maintenance: Systems like the STAR BRITE Aqua Flush help maintain water quality after storage. Regular cleaning reduces odors and sediment buildup.
- Installation Versatility: Some tanks are designed for under-mount installation, while others are portable. Your choice should align with your vehicle layout and DIY comfort level.
Frequently Asked Questions
- What is the best capacity for a family RV with limited storage? A: Larger fresh water tanks (e.g., 30–36 gallons) provide longer intervals between refills, but choose according to your available underbody space and water usage.
- Are under-mount water tanks safe for drinking water? A: Yes, if the tank uses NSF-approved or BPA-free materials and is intended for potable water. Verify labels and installation requirements.
- Can I tow a waste tote behind my vehicle? A: Yes, models with heavy-duty wheels and tow adapters are designed for towing behind a truck or golf cart. Check local regulations and safe towing practices.
- How do I prevent odors from waste tanks? A: Use proper venting, secure seals, and routine cleaning of connections. Consider a dedicated waste tank with a reliable gate valve.
- What maintenance is needed for fresh-water tanks? A: Regular flushing, periodic cleaning with approved tank cleaners, and inspection of fittings to prevent leaks.
- Do these tanks require professional installation? A: Some under-mount models may, depending on your RV’s construction. Portable totes generally require basic setup and hose connections.