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

  • 34 Gallon Marine Water Tank MW-482. Technical drawing of a polyethylene water tank designed for marine vessels.

    34 Gallon Marine Water Tank MW-482

    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 34 Gallon Marine Water Tank, Part# MW-482, is engineered to meet the requirements of mobile...

    MSRP: $323.90
    $307.95
    Add to Cart
  • 34 Gallon Marine Water Tank MW-234. Technical drawing of a polyethylene water tank designed for marine vessels.

    34 Gallon Marine Water Tank MW-234

    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 34 Gallon Marine Water Tank, Part# MW-234, is engineered to meet the requirements of mobile...

    MSRP: $393.45
    $374.09
    Add to Cart
  • 34 Gallon RV Holding Tank H-621. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    34 Gallon RV Holding Tank H-621

    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 34 Gallon RV Holding Tank, Part# H-621, is engineered to meet the requirements of mobile...

    MSRP: $220.31
    $209.47
    Add to Cart
  • 34 Gallon RV Holding Tank H-392 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    34 Gallon RV Holding Tank H-392

    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 34 Gallon RV Holding Tank, Part# H-392, is engineered to meet the requirements of mobile...

    MSRP: $233.27
    $221.79
    Add to Cart
  • 34 Gallon RV Holding Tank H-370 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    34 Gallon RV Holding Tank H-370

    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 34 Gallon RV Holding Tank, Part# H-370, is engineered to meet the requirements of mobile...

    MSRP: $272.15
    $258.76
    Add to Cart
  • 34 Gallon RV Holding Tank H-369 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    34 Gallon RV Holding Tank H-369

    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 34 Gallon RV Holding Tank, Part# H-369, is engineered to meet the requirements of mobile...

    MSRP: $333.10
    $316.70
    Add to Cart
  • 34 Gallon RV Holding Tank H-212. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    34 Gallon RV Holding Tank H-212

    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 34 Gallon RV Holding Tank, Part# H-212, is engineered to meet the requirements of mobile...

    MSRP: $233.27
    $221.79
    Add to Cart
  • An image of a 7 Gallon Marine Fresh Water Tank | B287

    35 Gallon RV Fresh Water Tank | RVB147

    This 35-gallon Ronco RV fresh water tank (RVB147) provides reliable potable water storage for recreational vehicles. Measuring 48" x 17" x 10", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $322.36
    Add to Cart
  • An image of a 150 Gallon RV Fresh Water Tank | B494

    35 Gallon RV Holding Tank | RV93H

    This 35-gallon Ronco RV holding tank (RV93H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 34" x 24" x 15", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $562.37
    Add to Cart
  • An image of a 150 Gallon Marine Fresh Water Tank | B494

    35 Gallon RV Holding Tank | RV90H

    This 35-gallon Ronco RV holding tank (RV90H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 42" x 24" x 12", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $562.37
    Add to Cart
  • An image of a 13 Gallon Marine Fresh Water Tank | BOAT37W

    35 Gallon RV Holding Tank | RV4H

    This 35-gallon Ronco RV holding tank (RV4H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 54" x 25" x 8", it fits common RV underbelly and compartment configurations while providing reliable waste containment...

    $362.53
    Add to Cart
  • An image of a 48 Gallon RV Holding Tank | RV92H

    35 Gallon RV Holding Tank | RV3H

    This 35-gallon Ronco RV holding tank (RV3H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 64" x 32" x 8", it fits common RV underbelly and compartment configurations while providing reliable waste containment...

    $527.23
    Add to Cart
  • An image of a 40 Gallon Marine Holding Tank | B256

    35 Gallon RV Fresh Water Tank | RV34W

    This 35-gallon Ronco RV fresh water tank (RV34W) provides reliable potable water storage for recreational vehicles. Measuring 33 1/2" x 16" x 19", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $449.89
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B349

    35 Gallon RV Fresh Water Tank | RV2W

    This 35-gallon Ronco RV fresh water tank (RV2W) provides reliable potable water storage for recreational vehicles. Measuring 37 1/2" x 19" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $372.57
    Add to Cart
  • An image of a 10 Gallon Marine Fresh Water Tank | B365

    35 Gallon RV Fresh Water Tank | RV1W

    This 35-gallon Ronco RV fresh water tank (RV1W) provides reliable potable water storage for recreational vehicles. Measuring 32 1/8" x 19 1/2" x 15", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $375.58
    Add to Cart
  • An image of a 21 Gallon RV Holding Tank | RV78H

    35 Gallon RV Holding Tank | RV101H

    This 35-gallon Ronco RV holding tank (RV101H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 62" x 31" x 6", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $292.23
    Add to Cart
  • An image of a 12 Gallon Marine Fresh Water Tank | B441

    35 Gallon Marine Fresh Water Tank | BOAT7W

    This 35-gallon Ronco marine fresh water tank (BOAT7W) is built for onboard potable water storage on boats and watercraft. Measuring 30" x 22" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $362.53
    Add to Cart
  • An image of a 44 Gallon Marine Fresh Water Tank | B440

    35 Gallon Marine Holding Tank | BOAT7W

    This 35-gallon Ronco marine holding tank (BOAT7W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 30" x 22" x 14", it is designed to fit common marine compartment layouts while providing dependable waste...

    $362.53
    Add to Cart
  • An image of a 25 Gallon Marine Fresh Water Tank | B180

    35 Gallon Marine Fresh Water Tank | BOAT6W

    This 35-gallon Ronco marine fresh water tank (BOAT6W) is built for onboard potable water storage on boats and watercraft. Measuring 48 3/8" x 14 3/8" x 13 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for...

    $362.53
    Add to Cart
  • An image of a 25 Gallon Marine Holding Tank | B180

    35 Gallon Marine Holding Tank | BOAT6W

    This 35-gallon Ronco marine holding tank (BOAT6W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 48 3/8" x 14 3/8" x 13 1/4", it is designed to fit common marine compartment layouts while providing...

    $362.53
    Add to Cart
  • An image of a 9 Gallon Marine Holding Tank | B341

    35 Gallon Marine Fresh Water Tank | BOAT38W

    This 35-gallon Ronco marine fresh water tank (BOAT38W) is built for onboard potable water storage on boats and watercraft. Measuring 45" x 18 1/2" x 11 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $362.53
    Add to Cart
  • An image of a 36 Gallon Marine Fresh Water Tank | B340

    35 Gallon Marine Holding Tank | BOAT38W

    This 35-gallon Ronco marine holding tank (BOAT38W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 45" x 18 1/2" x 11 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $362.53
    Add to Cart
  • An image of a 10 Gallon Marine Holding Tank | B365

    35 Gallon Marine Fresh Water Tank | BOAT1W

    This 35-gallon Ronco marine fresh water tank (BOAT1W) is built for onboard potable water storage on boats and watercraft. Measuring 32 1/8" x 19 1/2" x 15", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $339.43
    Add to Cart
  • An image of a 16 Gallon Marine Fresh Water Tank | B364

    35 Gallon Marine Holding Tank | BOAT1W

    This 35-gallon Ronco marine holding tank (BOAT1W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 32 1/8" x 19 1/2" x 15", it is designed to fit common marine compartment layouts while providing dependable...

    $339.43
    Add to Cart
  • An image of a 32 Gallon RV Fresh Water Tank | RVB316

    35 Gallon Marine Fresh Water Tank | B460

    This 35-gallon Ronco marine fresh water tank (B460) is built for onboard potable water storage on boats and watercraft. Measuring 36 1/2" x 37 3/8" x 11 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $515.18
    Add to Cart
  • An image of a 52 Gallon RV Fresh Water Tank | RVB315

    35 Gallon Marine Holding Tank | B460

    This 35-gallon Ronco marine holding tank (B460) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 36 1/2" x 37 3/8" x 11 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $515.18
    Add to Cart
  • An image of a 5 Gallon Marine Fresh Water Tank | B268

    35 Gallon Marine Fresh Water Tank | B445

    This 35-gallon Ronco marine fresh water tank (B445) is built for onboard potable water storage on boats and watercraft. Measuring 44" x 16 7/8" x 23", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $492.07
    Add to Cart
  • An image of a 5 Gallon Marine Holding Tank | B268

    35 Gallon Marine Holding Tank | B445

    This 35-gallon Ronco marine holding tank (B445) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 44" x 16 7/8" x 23", it is designed to fit common marine compartment layouts while providing dependable waste...

    $492.07
    Add to Cart
  • An image of a 65 Gallon RV Fresh Water Tank | B248

    35 Gallon Marine Fresh Water Tank | B431

    This 35-gallon Ronco marine fresh water tank (B431) is built for onboard potable water storage on boats and watercraft. Measuring 54" x 16" x 16", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $492.07
    Add to Cart
  • An image of a 65 Gallon Marine Fresh Water Tank | B248

    35 Gallon Marine Holding Tank | B431

    This 35-gallon Ronco marine holding tank (B431) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 54" x 16" x 16", it is designed to fit common marine compartment layouts while providing dependable waste...

    $492.07
    Add to Cart
  • An image of a 25 Gallon Marine Holding Tank | B171

    35 Gallon Marine Fresh Water Tank | B371

    This 35-gallon Ronco marine fresh water tank (B371) is built for onboard potable water storage on boats and watercraft. Measuring 67" x 14" x 10", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $421.77
    Add to Cart
  • An image of a 28 Gallon Marine Fresh Water Tank | B170

    35 Gallon Marine Holding Tank | B371

    This 35-gallon Ronco marine holding tank (B371) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 67" x 14" x 10", it is designed to fit common marine compartment layouts while providing dependable waste...

    $421.77
    Add to Cart