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

  • 80 Gallon RV Water Tank W-426. Technical drawing of a polyethylene water tank designed for your rv.

    80 Gallon RV Water Tank W-426

    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 80 Gallon RV Water Tank, Part# W-426, is engineered to meet the requirements of mobile water...

    MSRP: $414.71
    $394.29
    Add to Cart
  • 80 Gallon RV Water Tank W-251. Technical drawing of a polyethylene water tank designed for your rv.

    80 Gallon RV Water Tank W-251

    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 80 Gallon RV Water Tank, Part# W-251, is engineered to meet the requirements of mobile water...

    MSRP: $518.38
    $492.87
    Add to Cart
  • 80 Gallon Marine Water Tank MW-540. Technical drawing of a polyethylene water tank designed for marine vessels.

    80 Gallon Marine Water Tank MW-540

    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 80 Gallon Marine Water Tank, Part# MW-540, is engineered to meet the requirements of mobile...

    MSRP: $547.52
    $520.56
    Add to Cart
  • 80 Gallon Marine Water Tank MW-426. Technical drawing of a polyethylene water tank designed for marine vessels.

    80 Gallon Marine Water Tank MW-426

    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 80 Gallon Marine Water Tank, Part# MW-426, is engineered to meet the requirements of mobile...

    MSRP: $538.89
    $512.35
    Add to Cart
  • 80 Gallon Marine Water Tank MW-251. Technical drawing of a polyethylene water tank designed for marine vessels.

    80 Gallon Marine Water Tank MW-251

    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 80 Gallon Marine Water Tank, Part# MW-251, is engineered to meet the requirements of mobile...

    MSRP: $755.28
    $718.10
    Add to Cart
  • 80 Gallon RV Holding Tank H-674. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    80 Gallon RV Holding Tank H-674

    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 80 Gallon RV Holding Tank, Part# H-674, is engineered to meet the requirements of mobile...

    MSRP: $777.57
    $739.29
    Add to Cart
  • 80 Gallon RV Holding Tank H-557 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    80 Gallon RV Holding Tank H-557

    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 80 Gallon RV Holding Tank, Part# H-557, is engineered to meet the requirements of mobile...

    MSRP: $362.87
    $345.01
    Add to Cart
  • 80 Gallon RV Holding Tank H-544 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    80 Gallon RV Holding Tank H-544

    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 80 Gallon RV Holding Tank, Part# H-544, is engineered to meet the requirements of mobile...

    MSRP: $285.11
    $271.08
    Add to Cart
  • 81 Gallon RV Water Tank W-281. Technical drawing of a polyethylene water tank designed for your rv.

    81 Gallon RV Water Tank W-281

    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 81 Gallon RV Water Tank, Part# W-281, is engineered to meet the requirements of mobile water...

    MSRP: $408.23
    $388.12
    Add to Cart
  • 81 Gallon Marine Water Tank MW-281. Technical drawing of a polyethylene water tank designed for marine vessels.

    81 Gallon Marine Water Tank MW-281

    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 81 Gallon Marine Water Tank, Part# MW-281, is engineered to meet the requirements of mobile...

    MSRP: $652.30
    $620.19
    Add to Cart
  • An image of a 18 Gallon Marine Fresh Water Tank | B192

    82 Gallon Marine Fresh Water Tank | B454

    This 82-gallon Ronco marine fresh water tank (B454) is built for onboard potable water storage on boats and watercraft. Measuring 55" x 14 3/4" x 30 1/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $819.46
    Add to Cart
  • An image of a 18 Gallon Marine Holding Tank | B192

    82 Gallon Marine Holding Tank | B454

    This 82-gallon Ronco marine holding tank (B454) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 55" x 14 3/4" x 30 1/8", it is designed to fit common marine compartment layouts while providing dependable...

    $819.46
    Add to Cart
  • 82 Gallon RV Holding Tank H-390 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    82 Gallon RV Holding Tank H-390

    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 82 Gallon RV Holding Tank, Part# H-390, is engineered to meet the requirements of mobile...

    MSRP: $401.75
    $381.97
    Add to Cart
  • 83 Gallon RV Water Tank W-553. Technical drawing of a polyethylene water tank designed for your rv.

    83 Gallon RV Water Tank W-553

    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 83 Gallon RV Water Tank, Part# W-553, is engineered to meet the requirements of mobile water...

    MSRP: $777.57
    $739.29
    Add to Cart
  • 83 Gallon Marine Water Tank MW-553. Technical drawing of a polyethylene water tank designed for marine vessels.

    83 Gallon Marine Water Tank MW-553

    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 83 Gallon Marine Water Tank, Part# MW-553, is engineered to meet the requirements of mobile...

    MSRP: $704.22
    $669.55
    Add to Cart
  • 84 Gallon RV Holding Tank H-519. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    84 Gallon RV Holding Tank H-519

    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 84 Gallon RV Holding Tank, Part# H-519, is engineered to meet the requirements of mobile...

    MSRP: $216.41
    $205.76
    Add to Cart
  • 85 Gallon RV Water Tank W-550. Technical drawing of a polyethylene water tank designed for your rv.

    85 Gallon RV Water Tank W-550

    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 85 Gallon RV Water Tank, Part# W-550, is engineered to meet the requirements of mobile water...

    MSRP: $622.06
    $591.44
    Add to Cart
  • 85 Gallon RV Water Tank W-549. Technical drawing of a polyethylene water tank designed for your rv.

    85 Gallon RV Water Tank W-549

    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 85 Gallon RV Water Tank, Part# W-549, is engineered to meet the requirements of mobile water...

    MSRP: $557.26
    $529.82
    Add to Cart
  • 85 Gallon Marine Water Tank MW-550. Technical drawing of a polyethylene water tank designed for marine vessels.

    85 Gallon Marine Water Tank MW-550

    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 85 Gallon Marine Water Tank, Part# MW-550, is engineered to meet the requirements of mobile...

    MSRP: $1,186.92
    $1,128.49
    Add to Cart
  • 85 Gallon Marine Water Tank MW-549. Technical drawing of a polyethylene water tank designed for marine vessels.

    85 Gallon Marine Water Tank MW-549

    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 85 Gallon Marine Water Tank, Part# MW-549, is engineered to meet the requirements of mobile...

    MSRP: $918.71
    $873.48
    Add to Cart
  • 85 Gallon Marine Water Tank MW-487. Technical drawing of a polyethylene water tank designed for marine vessels.

    85 Gallon Marine Water Tank MW-487

    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 85 Gallon Marine Water Tank, Part# MW-487, is engineered to meet the requirements of mobile...

    MSRP: $912.46
    $867.55
    Add to Cart
  • An image of a 5 Gallon RV Fresh Water Tank | RVB322

    86 Gallon Marine Fresh Water Tank | BOAT64W

    This 86-gallon Ronco marine fresh water tank (BOAT64W) is built for onboard potable water storage on boats and watercraft. Measuring 39 1/4" x 39 1/4" x 14 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for...

    $608.57
    Add to Cart
  • An image of a 9 Gallon RV Fresh Water Tank | RVB321

    86 Gallon Marine Holding Tank | BOAT64W

    This 86-gallon Ronco marine holding tank (BOAT64W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 39 1/4" x 39 1/4" x 14 1/2", it is designed to fit common marine compartment layouts while providing...

    $608.57
    Add to Cart
  • 89 Gallon RV Holding Tank H-653. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    89 Gallon RV Holding Tank H-653

    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 89 Gallon RV Holding Tank, Part# H-653, is engineered to meet the requirements of mobile...

    MSRP: $583.18
    $554.47
    Add to Cart
  • An image of a 10 Gallon RV Fresh Water Tank | RVB323

    90 Gallon RV Fresh Water Tank | RV64W

    This 90-gallon Ronco RV fresh water tank (RV64W) provides reliable potable water storage for recreational vehicles. Measuring 39 1/4" x 39 1/4" x 14 1/2", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $550.32
    Add to Cart
  • An image of a 9 Gallon RV Fresh Water Tank | RVB132

    90 Gallon RV Fresh Water Tank | B314

    This 90-gallon Ronco RV fresh water tank (B314) provides reliable potable water storage for recreational vehicles. Measuring 34" x 32" x 21", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $666.81
    Add to Cart
  • An image of a 15 Gallon RV Fresh Water Tank | RVB131

    90 Gallon Marine Fresh Water Tank | B314

    This 90-gallon Ronco marine fresh water tank (B314) is built for onboard potable water storage on boats and watercraft. Measuring 34" x 32" x 21", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $666.81
    Add to Cart
  • An image of a 22 Gallon RV Fresh Water Tank | RVB128

    90 Gallon Marine Holding Tank | B314

    This 90-gallon Ronco marine holding tank (B314) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 34" x 32" x 21", it is designed to fit common marine compartment layouts while providing dependable waste...

    $666.81
    Add to Cart
  • An image of a 35 Gallon RV Fresh Water Tank | RV2W

    90 Gallon RV Fresh Water Tank | B204

    This 90-gallon Ronco RV fresh water tank (B204) provides reliable potable water storage for recreational vehicles. Measuring 76" x 27" x 11 1/2", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $689.91
    Add to Cart
  • An image of a 17 Gallon RV Holding Tank | RV2H

    90 Gallon Marine Fresh Water Tank | B204

    This 90-gallon Ronco marine fresh water tank (B204) is built for onboard potable water storage on boats and watercraft. Measuring 76" x 27" x 11 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $689.91
    Add to Cart
  • An image of a 16 Gallon RV Holding Tank | RV29H

    90 Gallon Marine Holding Tank | B204

    This 90-gallon Ronco marine holding tank (B204) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 76" x 27" x 11 1/2", it is designed to fit common marine compartment layouts while providing dependable waste...

    $689.91
    Add to Cart