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

  • 132 Gallon Marine Water Tank MW-347. Technical drawing of a polyethylene water tank designed for marine vessels.

    132 Gallon Marine Water Tank MW-347

    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 132 Gallon Marine Water Tank, Part# MW-347, is engineered to meet the requirements of mobile...

    MSRP: $1,108.34
    $1,053.77
    Add to Cart
  • An image of a 18 Gallon RV Fresh Water Tank | RVB232

    135 Gallon RV Fresh Water Tank | B407

    This 135-gallon Ronco RV fresh water tank (B407) provides reliable potable water storage for recreational vehicles. Measuring 75 1/2" x 33 1/4" x 14", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $876.71
    Add to Cart
  • An image of a 20 Gallon RV Fresh Water Tank | RVB231

    135 Gallon Marine Fresh Water Tank | B407

    This 135-gallon Ronco marine fresh water tank (B407) is built for onboard potable water storage on boats and watercraft. Measuring 75 1/2" x 33 1/4" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $876.71
    Add to Cart
  • An image of a 48 Gallon RV Fresh Water Tank | RVB229

    135 Gallon Marine Holding Tank | B407

    This 135-gallon Ronco marine holding tank (B407) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 75 1/2" x 33 1/4" x 14", it is designed to fit common marine compartment layouts while providing dependable...

    $876.71
    Add to Cart
  • An image of a 27 Gallon RV Holding Tank | RV47H

    135 Gallon RV Fresh Water Tank | B300

    This 135-gallon Ronco RV fresh water tank (B300) provides reliable potable water storage for recreational vehicles. Measuring 76" x 28" x 16", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $876.71
    Add to Cart
  • An image of a 13 Gallon RV Holding Tank | RV46H

    135 Gallon Marine Fresh Water Tank | B300

    This 135-gallon Ronco marine fresh water tank (B300) is built for onboard potable water storage on boats and watercraft. Measuring 76" x 28" x 16", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $876.71
    Add to Cart
  • An image of a 25 Gallon RV Holding Tank | RV45H

    135 Gallon Marine Holding Tank | B300

    This 135-gallon Ronco marine holding tank (B300) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 76" x 28" x 16", it is designed to fit common marine compartment layouts while providing dependable waste...

    $876.71
    Add to Cart
  • 135 Gallon RV Water Tank W-239. Technical drawing of a polyethylene water tank designed for your rv.

    135 Gallon RV Water Tank W-239

    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 135 Gallon RV Water Tank, Part# W-239, is engineered to meet the requirements of mobile water...

    MSRP: $583.18
    $554.47
    Add to Cart
  • 135 Gallon Marine Water Tank MW-239. Technical drawing of a polyethylene water tank designed for marine vessels.

    135 Gallon Marine Water Tank MW-239

    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 135 Gallon Marine Water Tank, Part# MW-239, is engineered to meet the requirements of mobile...

    MSRP: $1,226.50
    $1,166.11
    Add to Cart
  • 135 Gallon RV Holding Tank H-313 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    135 Gallon RV Holding Tank H-313

    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 135 Gallon RV Holding Tank, Part# H-313, is engineered to meet the requirements of mobile...

    MSRP: $686.85
    $653.04
    Add to Cart
  • 136 Gallon RV Holding Tank H-673. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    136 Gallon RV Holding Tank H-673

    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 136 Gallon RV Holding Tank, Part# H-673, is engineered to meet the requirements of mobile...

    MSRP: $997.88
    $948.75
    Add to Cart
  • An image of a 13 Gallon RV Fresh Water Tank | RVB266

    141 Gallon RV Fresh Water Tank | B484

    This 141-gallon Ronco RV fresh water tank (B484) provides reliable potable water storage for recreational vehicles. Measuring 53" x 35" x 19", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $900.81
    Add to Cart
  • An image of a 14 Gallon RV Fresh Water Tank | RVB265

    141 Gallon Marine Fresh Water Tank | B484

    This 141-gallon Ronco marine fresh water tank (B484) is built for onboard potable water storage on boats and watercraft. Measuring 53" x 35" x 19", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $900.81
    Add to Cart
  • An image of a 15 Gallon RV Fresh Water Tank | RVB264

    141 Gallon Marine Holding Tank | B484

    This 141-gallon Ronco marine holding tank (B484) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 53" x 35" x 19", it is designed to fit common marine compartment layouts while providing dependable waste...

    $900.81
    Add to Cart
  • 142 Gallon RV Water Tank W-474. Technical drawing of a polyethylene water tank designed for your rv.

    142 Gallon RV Water Tank W-474

    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 142 Gallon RV Water Tank, Part# W-474, is engineered to meet the requirements of mobile water...

    MSRP: $1,166.35
    $1,108.93
    Add to Cart
  • 142 Gallon RV Water Tank W-272. Technical drawing of a polyethylene water tank designed for your rv.

    142 Gallon RV Water Tank W-272

    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 142 Gallon RV Water Tank, Part# W-272, is engineered to meet the requirements of mobile water...

    MSRP: $557.26
    $529.82
    Add to Cart
  • 142 Gallon Marine Water Tank MW-474. Technical drawing of a polyethylene water tank designed for marine vessels.

    142 Gallon Marine Water Tank MW-474

    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 142 Gallon Marine Water Tank, Part# MW-474, is engineered to meet the requirements of mobile...

    MSRP: $870.96
    $828.08
    Add to Cart
  • 142 Gallon Marine Water Tank MW-272. Technical drawing of a polyethylene water tank designed for marine vessels.

    142 Gallon Marine Water Tank MW-272

    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 142 Gallon Marine Water Tank, Part# MW-272, is engineered to meet the requirements of mobile...

    MSRP: $1,167.85
    $1,110.35
    Add to Cart
  • 143 Gallon RV Water Tank W-508. Technical drawing of a polyethylene water tank designed for your rv.

    143 Gallon RV Water Tank W-508

    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 143 Gallon RV Water Tank, Part# W-508, is engineered to meet the requirements of mobile water...

    MSRP: $1,166.35
    $1,108.93
    Add to Cart
  • 143 Gallon Marine Water Tank MW-508. Technical drawing of a polyethylene water tank designed for marine vessels.

    143 Gallon Marine Water Tank MW-508

    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 143 Gallon Marine Water Tank, Part# MW-508, is engineered to meet the requirements of mobile...

    MSRP: $934.46
    $888.46
    Add to Cart
  • 145 Gallon RV Water Tank W-527. Technical drawing of a polyethylene water tank designed for your rv.

    145 Gallon RV Water Tank W-527

    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 145 Gallon RV Water Tank, Part# W-527, is engineered to meet the requirements of mobile water...

    MSRP: $1,088.59
    $1,035.01
    Add to Cart
  • An image of a 18 Gallon RV Fresh Water Tank | RVB159

    150 Gallon RV Fresh Water Tank | B494

    This 150-gallon Ronco RV fresh water tank (B494) provides reliable potable water storage for recreational vehicles. Measuring 40 1/4" x 32 1/2" x 28 1/2", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $923.90
    Add to Cart
  • An image of a 36 Gallon RV Fresh Water Tank | RVB158

    150 Gallon Marine Fresh Water Tank | B494

    This 150-gallon Ronco marine fresh water tank (B494) is built for onboard potable water storage on boats and watercraft. Measuring 40 1/4" x 32 1/2" x 28 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $923.90
    Add to Cart
  • An image of a 30 Gallon RV Fresh Water Tank | RVB157

    150 Gallon Marine Holding Tank | B494

    This 150-gallon Ronco marine holding tank (B494) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 40 1/4" x 32 1/2" x 28 1/2", it is designed to fit common marine compartment layouts while providing...

    $923.90
    Add to Cart
  • An image of a 43 Gallon RV Fresh Water Tank | RVB368

    150 Gallon Marine Fresh Water Tank | B411

    This 150-gallon Ronco marine fresh water tank (B411) is built for onboard potable water storage on boats and watercraft. Measuring 54" x 48 1/4" x 27", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips...

    $1,147.85
    Add to Cart
  • An image of a 18 Gallon RV Fresh Water Tank | RVB366

    150 Gallon Marine Holding Tank | B411

    This 150-gallon Ronco marine holding tank (B411) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 54" x 48 1/4" x 27", it is designed to fit common marine compartment layouts while providing dependable waste...

    $1,147.85
    Add to Cart
  • 150 Gallon RV Water Tank W-93. Technical drawing of a polyethylene water tank designed for your rv.

    150 Gallon RV Water Tank W-93

    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 150 Gallon RV Water Tank, Part# W-93, is engineered to meet the requirements of mobile water...

    MSRP: $725.73
    $690.01
    Add to Cart
  • 150 Gallon Marine Water Tank MW-93. Technical drawing of a polyethylene water tank designed for marine vessels.

    150 Gallon Marine Water Tank MW-93

    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 150 Gallon Marine Water Tank, Part# MW-93, is engineered to meet the requirements of mobile...

    MSRP: $1,244.69
    $1,183.42
    Add to Cart
  • 150 Gallon Marine Water Tank MW-108. Technical drawing of a polyethylene water tank designed for marine vessels.

    150 Gallon Marine Water Tank MW-108

    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 150 Gallon Marine Water Tank, Part# MW-108, is engineered to meet the requirements of mobile...

    MSRP: $865.30
    $822.70
    Add to Cart
  • An image of a 24 Gallon Marine Fresh Water Tank | B564

    155 Gallon RV Fresh Water Tank | B392

    This 155-gallon Ronco RV fresh water tank (B392) provides reliable potable water storage for recreational vehicles. Measuring 67" x 24" x 24", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $923.90
    Add to Cart
  • An image of a 24 Gallon Marine Holding Tank | B564

    155 Gallon Marine Fresh Water Tank | B392

    This 155-gallon Ronco marine fresh water tank (B392) is built for onboard potable water storage on boats and watercraft. Measuring 67" x 24" x 24", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $923.90
    Add to Cart