Marine and RV Water and Holding Tanks for Sale

Pick the size, the shape, and the fitting locations to make a perfect fit for your Marine or RV Water and Holding Tank replacement.   You won’t find better-made RV or Marine holding tanks for the price.

Made from one piece to form 3/8"; thick walls using a roto-mold process to create a seamless holding tank superior in strength and performance. The bottom line: These tanks are nearly unbreakable and are built to go the distance, at sea or on the road.

Fittings: You customize the placement of the fittings when you place the order. We spin-weld the fittings to ensure your holding tank is securely connected to your plumbing.

  • Complies with NSF 61, FDA Reg CFR 177.1520, and Coast Guard Standards
  • Made from virgin polyethylene (poly) resins
  • Seamless tank made from one piece (less likely to break or leak)
  • 3/8” thick tank walls
  • Customized fitting placement
  • Spin weld fittings
  • Outlasts the competition

For use as RV freshwater tanks, RV holding tanks, RV black water holding tanks, RV waste holding tanks, Marine fresh water tanks, Marine holding tanks, and more!

We have 100's of sizes ranging from 2 gallons, 40 gallons, 50 gallons, 100 gallons, up to 250 gallons for these marine and rv fresh water and holding tanks.

  • Marine Holding Tanks
  • Marine Water Tanks
  • RV holding Tanks
  • RV Water Tanks
  • RV Black Water Tanks

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RV & Marine Tanks

  • An image of a 9 Gallon Marine Fresh Water Tank | B361

    11 Gallon Marine Holding Tank | B319

    This 11-gallon Ronco marine holding tank (B319) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 35" x 19 1/2" x 4 3/4", it is designed to fit common marine compartment layouts while providing dependable...

    $209.88
    Add to Cart
  • An image of a 13 Gallon Marine Fresh Water Tank | B144

    11 Gallon Marine Fresh Water Tank | B286

    This 11-gallon Ronco marine fresh water tank (B286) is built for onboard potable water storage on boats and watercraft. Measuring 15 3/8" x 13 1/2" x 13 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $197.83
    Add to Cart
  • An image of a 13 Gallon Marine Holding Tank | B144

    11 Gallon Marine Holding Tank | B286

    This 11-gallon Ronco marine holding tank (B286) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 15 3/8" x 13 1/2" x 13 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $197.83
    Add to Cart
  • 11 Gallon RV Water Tank W-210. Technical drawing of a polyethylene water tank designed for your rv.

    11 Gallon RV Water Tank W-210

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Water Tank, Part# W-210, is engineered to meet the requirements of mobile water...

    MSRP: $75.13
    $71.43
    Add to Cart
  • 11 Gallon Marine Water Tank MW-521. Technical drawing of a polyethylene water tank designed for marine vessels.

    11 Gallon Marine Water Tank MW-521

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon Marine Water Tank, Part# MW-521, is engineered to meet the requirements of mobile...

    MSRP: $166.86
    $158.64
    Add to Cart
  • 11 Gallon Marine Water Tank MW-491. Technical drawing of a polyethylene water tank designed for marine vessels.

    11 Gallon Marine Water Tank MW-491

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon Marine Water Tank, Part# MW-491, is engineered to meet the requirements of mobile...

    MSRP: $133.05
    $126.50
    Add to Cart
  • 11 Gallon Marine Water Tank MW-210. Technical drawing of a polyethylene water tank designed for marine vessels.

    11 Gallon Marine Water Tank MW-210

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon Marine Water Tank, Part# MW-210, is engineered to meet the requirements of mobile...

    MSRP: $191.89
    $182.44
    Add to Cart
  • 11 Gallon RV Holding Tank H-672. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-672

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-672, is engineered to meet the requirements of mobile...

    MSRP: $142.56
    $135.54
    Add to Cart
  • 11 Gallon RV Holding Tank H-576 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-576

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-576, is engineered to meet the requirements of mobile...

    MSRP: $155.52
    $147.87
    Add to Cart
  • 11 Gallon RV Holding Tank H-324 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-324

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-324, is engineered to meet the requirements of mobile...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 11 Gallon RV Holding Tank H-306 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-306

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-306, is engineered to meet the requirements of mobile...

    MSRP: $97.20
    $92.41
    Add to Cart
  • 11 Gallon RV Holding Tank H-269 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-269

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-269, is engineered to meet the requirements of mobile...

    MSRP: $129.60
    $123.22
    Add to Cart
  • 11 Gallon RV Holding Tank H-263 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-263

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-263, is engineered to meet the requirements of mobile...

    MSRP: $129.60
    $123.22
    Add to Cart
  • 11 Gallon RV Holding Tank H-220. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    11 Gallon RV Holding Tank H-220

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 11 Gallon RV Holding Tank, Part# H-220, is engineered to meet the requirements of mobile...

    MSRP: $129.60
    $123.22
    Add to Cart
  • An image of a 20 Gallon Marine Fresh Water Tank | B146

    12 Gallon RV Fresh Water Tank | RVB548

    This 12-gallon Ronco RV fresh water tank (RVB548) provides reliable potable water storage for recreational vehicles. Measuring 24" x 13 1/2" x 10", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $199.84
    Add to Cart
  • An image of a 6 Gallon RV Fresh Water Tank | RVB404

    12 Gallon RV Fresh Water Tank | RVB441

    This 12-gallon Ronco RV fresh water tank (RVB441) provides reliable potable water storage for recreational vehicles. Measuring 14 3/4" x 14 3/4" x 14 1/4", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $201.85
    Add to Cart
  • An image of a 43 Gallon PE Ronco White Rectangular Open Top Tank | 30X20X18PE

    12 Gallon RV Fresh Water Tank | RVB279

    This 12-gallon Ronco RV fresh water tank (RVB279) provides reliable potable water storage for recreational vehicles. Measuring 23" x 11 1/2" x 11 1/2", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $136.57
    Add to Cart
  • An image of a 14 Gallon Marine Holding Tank | B274

    12 Gallon RV Fresh Water Tank | RVB255

    This 12-gallon Ronco RV fresh water tank (RVB255) provides reliable potable water storage for recreational vehicles. Measuring 17" x 17" x 11", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $181.76
    Add to Cart
  • An image of a 125 Gallon PE Ronco White Rectangular Open Top Tank | 36X24X36PE

    12 Gallon RV Fresh Water Tank | RVB124

    This 12-gallon Ronco RV fresh water tank (RVB124) provides reliable potable water storage for recreational vehicles. Measuring 20" x 12" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $136.57
    Add to Cart
  • An image of a 28 Gallon Marine Fresh Water Tank | B161

    12 Gallon RV Fresh Water Tank | RVB105

    This 12-gallon Ronco RV fresh water tank (RVB105) provides reliable potable water storage for recreational vehicles. Measuring 17 1/2" x 14" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $134.56
    Add to Cart
  • An image of a 45 Gallon Marine Holding Tank | B155

    12 Gallon RV Holding Tank | RV44H

    This 12-gallon Ronco RV holding tank (RV44H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 81" x 14" x 7", it fits common RV underbelly and compartment configurations while providing reliable waste containment...

    $281.18
    Add to Cart
  • An image of a 5 Gallon Marine Fresh Water Tank | B410

    12 Gallon RV Holding Tank | RV41H

    This 12-gallon Ronco RV holding tank (RV41H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 28" x 21" x 10", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $222.93
    Add to Cart
  • An image of a 22 Gallon Marine Holding Tank | B117

    12 Gallon RV Fresh Water Tank | RV16W

    This 12-gallon Ronco RV fresh water tank (RV16W) provides reliable potable water storage for recreational vehicles. Measuring 18" x 13" x 13", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $199.84
    Add to Cart
  • An image of a 43 Gallon Marine Holding Tank | B220

    12 Gallon RV Fresh Water Tank | RV14W

    This 12-gallon Ronco RV fresh water tank (RV14W) provides reliable potable water storage for recreational vehicles. Measuring 24" x 15 1/2" x 8 1/4", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $199.84
    Add to Cart
  • An image of a 70 Gallon Marine Fresh Water Tank | B153

    12 Gallon Marine Fresh Water Tank | BOAT3W

    This 12-gallon Ronco marine fresh water tank (BOAT3W) is built for onboard potable water storage on boats and watercraft. Measuring 29 3/4" x 13 7/8" x 8 1/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $233.99
    Add to Cart
  • An image of a 70 Gallon Marine Holding Tank | B153

    12 Gallon Marine Holding Tank | BOAT3W

    This 12-gallon Ronco marine holding tank (BOAT3W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 29 3/4" x 13 7/8" x 8 1/8", it is designed to fit common marine compartment layouts while providing...

    $233.99
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B146

    12 Gallon Marine Fresh Water Tank | B548

    This 12-gallon Ronco marine fresh water tank (B548) is built for onboard potable water storage on boats and watercraft. Measuring 24" x 13 1/2" x 10", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $232.98
    Add to Cart
  • An image of a 26 Gallon Marine Fresh Water Tank | B145

    12 Gallon Marine Holding Tank | B548

    This 12-gallon Ronco marine holding tank (B548) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 24" x 13 1/2" x 10", it is designed to fit common marine compartment layouts while providing dependable waste...

    $232.98
    Add to Cart
  • An image of a 5 Gallon RV Fresh Water Tank | RVB390

    12 Gallon Marine Fresh Water Tank | B441

    This 12-gallon Ronco marine fresh water tank (B441) is built for onboard potable water storage on boats and watercraft. Measuring 14 3/4" x 14 3/4" x 14 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $232.98
    Add to Cart
  • An image of a 10 Gallon RV Fresh Water Tank | RVB389

    12 Gallon Marine Holding Tank | B441

    This 12-gallon Ronco marine holding tank (B441) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 14 3/4" x 14 3/4" x 14 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $232.98
    Add to Cart
  • An image of a 77 Gallon PP Ronco White Rectangular Open Top Tank | 30x18x36PP

    12 Gallon Marine Fresh Water Tank | B279

    This 12-gallon Ronco marine fresh water tank (B279) is built for onboard potable water storage on boats and watercraft. Measuring 23" x 11 1/2" x 11 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $232.98
    Add to Cart
  • An image of a 77 Gallon PE Ronco White Rectangular Open Top Tank | 30X18X36PE

    12 Gallon Marine Holding Tank | B279

    This 12-gallon Ronco marine holding tank (B279) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 23" x 11 1/2" x 11 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $232.98
    Add to Cart