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 53 Gallon Marine Fresh Water Tank | B545

    110 Gallon Marine Fresh Water Tank | B298

    This 110-gallon Ronco marine fresh water tank (B298) is built for onboard potable water storage on boats and watercraft. Measuring 76" x 24" x 15 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips...

    $701.97
    Add to Cart
  • An image of a 53 Gallon Marine Holding Tank | B545

    110 Gallon Marine Holding Tank | B298

    This 110-gallon Ronco marine holding tank (B298) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 76" x 24" x 15 1/2", it is designed to fit common marine compartment layouts while providing dependable waste...

    $701.97
    Add to Cart
  • An image of a 35 Gallon RV Fresh Water Tank | RV34W

    115 Gallon RV Fresh Water Tank | B466

    This 115-gallon Ronco RV fresh water tank (B466) provides reliable potable water storage for recreational vehicles. Measuring 54" x 27" x 20", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $748.16
    Add to Cart
  • An image of a 10 Gallon RV Holding Tank | RV34H

    115 Gallon Marine Fresh Water Tank | B466

    This 115-gallon Ronco marine fresh water tank (B466) is built for onboard potable water storage on boats and watercraft. Measuring 54" x 27" x 20", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $748.16
    Add to Cart
  • An image of a 46 Gallon RV Fresh Water Tank | RV33W

    115 Gallon Marine Holding Tank | B466

    This 115-gallon Ronco marine holding tank (B466) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 54" x 27" x 20", it is designed to fit common marine compartment layouts while providing dependable waste...

    $748.16
    Add to Cart
  • An image of a 58 Gallon RV Fresh Water Tank | RV44W

    115 Gallon RV Fresh Water Tank | B328

    This 115-gallon Ronco RV fresh water tank (B328) provides reliable potable water storage for recreational vehicles. Measuring 39 1/2" x 28" x 26", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $748.16
    Add to Cart
  • An image of a 12 Gallon RV Holding Tank | RV44H

    115 Gallon Marine Fresh Water Tank | B328

    This 115-gallon Ronco marine fresh water tank (B328) is built for onboard potable water storage on boats and watercraft. Measuring 39 1/2" x 28" x 26", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips...

    $748.16
    Add to Cart
  • An image of a 58 Gallon RV Fresh Water Tank | RV43W

    115 Gallon Marine Holding Tank | B328

    This 115-gallon Ronco marine holding tank (B328) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 39 1/2" x 28" x 26", it is designed to fit common marine compartment layouts while providing dependable waste...

    $748.16
    Add to Cart
  • 115 Gallon RV Holding Tank H-166 (OR). Technical drawing of a polyethylene holding tank designed for your rv and camper.

    115 Gallon RV Holding Tank H-166 (OR)

    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 115 Gallon RV Holding Tank, Part# H-166 (OR), is engineered to meet the requirements of mobile...

    MSRP: $505.42
    $480.54
    Add to Cart
  • 120 Gallon Marine Water Tank MW-437. Technical drawing of a polyethylene water tank designed for marine vessels.

    120 Gallon Marine Water Tank MW-437

    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 120 Gallon Marine Water Tank, Part# MW-437, is engineered to meet the requirements of mobile...

    MSRP: $2,176.46
    $2,069.31
    Add to Cart
  • 120 Gallon RV Holding Tank H-366 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    120 Gallon RV Holding Tank H-366

    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 120 Gallon RV Holding Tank, Part# H-366, is engineered to meet the requirements of mobile...

    MSRP: $453.58
    $431.25
    Add to Cart
  • 123 Gallon RV Holding Tank H-669. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    123 Gallon RV Holding Tank H-669

    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 123 Gallon RV Holding Tank, Part# H-669, is engineered to meet the requirements of mobile...

    MSRP: $725.73
    $690.01
    Add to Cart
  • 123 Gallon RV Holding Tank H-331 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    123 Gallon RV Holding Tank H-331

    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 123 Gallon RV Holding Tank, Part# H-331, is engineered to meet the requirements of mobile...

    MSRP: $622.06
    $591.44
    Add to Cart
  • An image of a 16 Gallon RV Holding Tank | RV58H

    125 Gallon RV Fresh Water Tank | B247

    This 125-gallon Ronco RV fresh water tank (B247) provides reliable potable water storage for recreational vehicles. Measuring 43 1/8" x 29 7/8" x 24", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $865.65
    Add to Cart
  • An image of a 20 Gallon RV Fresh Water Tank | RV57W

    125 Gallon Marine Fresh Water Tank | B247

    This 125-gallon Ronco marine fresh water tank (B247) is built for onboard potable water storage on boats and watercraft. Measuring 43 1/8" x 29 7/8" x 24", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $865.65
    Add to Cart
  • An image of a 16 Gallon RV Holding Tank | RV57H

    125 Gallon Marine Holding Tank | B247

    This 125-gallon Ronco marine holding tank (B247) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 43 1/8" x 29 7/8" x 24", it is designed to fit common marine compartment layouts while providing dependable...

    $865.65
    Add to Cart
  • An image of a 18 Gallon RV Holding Tank | RV69H

    125 Gallon Marine Fresh Water Tank | B243

    This 125-gallon Ronco marine fresh water tank (B243) is built for onboard potable water storage on boats and watercraft. Measuring 53 1/2" x 30" x 19 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $912.86
    Add to Cart
  • An image of a 33 Gallon RV Holding Tank | RV68H

    125 Gallon Marine Holding Tank | B243

    This 125-gallon Ronco marine holding tank (B243) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 53 1/2" x 30" x 19 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $912.86
    Add to Cart
  • 125 Gallon RV Water Tank W-547. Technical drawing of a polyethylene water tank designed for your rv.

    125 Gallon RV Water Tank W-547

    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 125 Gallon RV Water Tank, Part# W-547, is engineered to meet the requirements of mobile water...

    MSRP: $492.46
    $468.22
    Add to Cart
  • 125 Gallon RV Water Tank W-238. Technical drawing of a polyethylene water tank designed for your rv.

    125 Gallon RV Water Tank W-238

    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 125 Gallon RV Water Tank, Part# W-238, is engineered to meet the requirements of mobile water...

    MSRP: $518.38
    $492.87
    Add to Cart
  • 125 Gallon Marine Water Tank MW-547. Technical drawing of a polyethylene water tank designed for marine vessels.

    125 Gallon Marine Water Tank MW-547

    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 125 Gallon Marine Water Tank, Part# MW-547, is engineered to meet the requirements of mobile...

    MSRP: $757.52
    $720.23
    Add to Cart
  • 125 Gallon Marine Water Tank MW-238. Technical drawing of a polyethylene water tank designed for marine vessels.

    125 Gallon Marine Water Tank MW-238

    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 125 Gallon Marine Water Tank, Part# MW-238, is engineered to meet the requirements of mobile...

    MSRP: $1,136.80
    $1,080.83
    Add to Cart
  • An image of a 8 Gallon RV Fresh Water Tank | RVB270

    130 Gallon Marine Fresh Water Tank | B467

    This 130-gallon Ronco marine fresh water tank (B467) is built for onboard potable water storage on boats and watercraft. Measuring 41 1/2" x 35 3/4" x 27", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $900.81
    Add to Cart
  • An image of a 4 Gallon RV Fresh Water Tank | RVB269

    130 Gallon Marine Holding Tank | B467

    This 130-gallon Ronco marine holding tank (B467) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 41 1/2" x 35 3/4" x 27", it is designed to fit common marine compartment layouts while providing dependable...

    $900.81
    Add to Cart
  • An image of a 36 Gallon RV Fresh Water Tank | RV6W

    130 Gallon RV Fresh Water Tank | B356

    This 130-gallon Ronco RV fresh water tank (B356) provides reliable potable water storage for recreational vehicles. Measuring 60" x 30" x 18", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $865.65
    Add to Cart
  • An image of a 27 Gallon RV Holding Tank | RV6H

    130 Gallon Marine Fresh Water Tank | B356

    This 130-gallon Ronco marine fresh water tank (B356) is built for onboard potable water storage on boats and watercraft. Measuring 60" x 30" x 18", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $865.65
    Add to Cart
  • An image of a 32 Gallon RV Fresh Water Tank | RV69W

    130 Gallon Marine Holding Tank | B356

    This 130-gallon Ronco marine holding tank (B356) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 60" x 30" x 18", it is designed to fit common marine compartment layouts while providing dependable waste...

    $865.65
    Add to Cart
  • 130 Gallon RV Water Tank W-565. Technical drawing of a polyethylene water tank designed for your rv.

    130 Gallon RV Water Tank W-565

    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 130 Gallon RV Water Tank, Part# W-565, is engineered to meet the requirements of mobile water...

    MSRP: $1,036.76
    $985.72
    Add to Cart
  • 130 Gallon Marine Water Tank MW-450. Technical drawing of a polyethylene water tank designed for marine vessels.

    130 Gallon Marine Water Tank MW-450

    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 130 Gallon Marine Water Tank, Part# MW-450, is engineered to meet the requirements of mobile...

    MSRP: $1,226.50
    $1,166.11
    Add to Cart
  • 132 Gallon RV Water Tank W-347. Technical drawing of a polyethylene water tank designed for your rv.

    132 Gallon RV Water Tank W-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 RV Water Tank, Part# W-347, is engineered to meet the requirements of mobile water...

    MSRP: $531.34
    $505.18
    Add to Cart