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

Shop by Category

RV & Marine Tanks

  • An image of a 36 Gallon Marine Fresh Water Tank | B428

    36 Gallon RV Fresh Water Tank | RVB158

    This 36-gallon Ronco RV fresh water tank (RVB158) provides reliable potable water storage for recreational vehicles. Measuring 30 1/2" x 21 1/2" x 13 3/4", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $295.24
    Add to Cart
  • An image of a 7 Gallon RV Fresh Water Tank | RVB272

    36 Gallon RV Holding Tank | RV85H

    This 36-gallon Ronco RV holding tank (RV85H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 52" x 36" x 12", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $456.93
    Add to Cart
  • An image of a 110 Gallon Marine Holding Tank | B433

    36 Gallon RV Fresh Water Tank | RV7W

    This 36-gallon Ronco RV fresh water tank (RV7W) provides reliable potable water storage for recreational vehicles. Measuring 30" x 22" x 14", 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 15 Gallon Marine Fresh Water Tank | B175

    36 Gallon RV Fresh Water Tank | RV6W

    This 36-gallon Ronco RV fresh water tank (RV6W) provides reliable potable water storage for recreational vehicles. Measuring 48 3/8" x 14 3/8" x 13 1/4", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $375.58
    Add to Cart
  • An image of a 13 Gallon Marine Holding Tank | BOAT37W

    36 Gallon RV Holding Tank | RV48H

    This 36-gallon Ronco RV holding tank (RV48H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 35" x 25" x 13", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $316.33
    Add to Cart
  • An image of a 22 Gallon Marine Fresh Water Tank | B337

    36 Gallon RV Fresh Water Tank | RV38W

    This 36-gallon Ronco RV fresh water tank (RV38W) provides reliable potable water storage for recreational vehicles. Measuring 45" x 18 1/2" x 11 1/4", 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 36 Gallon RV Fresh Water Tank | RV38W

    36 Gallon RV Holding Tank | RV37H

    This 36-gallon Ronco RV holding tank (RV37H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 35" x 28" x 16", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $386.63
    Add to Cart
  • An image of a 42 Gallon Marine Holding Tank | B443

    36 Gallon Marine Fresh Water Tank | B478

    This 36-gallon Ronco marine fresh water tank (B478) is built for onboard potable water storage on boats and watercraft. Measuring 24" x 22" x 19", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $362.53
    Add to Cart
  • An image of a 9 Gallon Marine Fresh Water Tank | B442

    36 Gallon Marine Holding Tank | B478

    This 36-gallon Ronco marine holding tank (B478) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 24" x 22" x 19", it is designed to fit common marine compartment layouts while providing dependable waste...

    $362.53
    Add to Cart
  • An image of a 7 Gallon RV Fresh Water Tank | RVB275

    36 Gallon Marine Fresh Water Tank | B428

    This 36-gallon Ronco marine fresh water tank (B428) is built for onboard potable water storage on boats and watercraft. Measuring 46" x 36" x 6", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $373.57
    Add to Cart
  • An image of a 14 Gallon RV Fresh Water Tank | RVB274

    36 Gallon Marine Holding Tank | B428

    This 36-gallon Ronco marine holding tank (B428) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 46" x 36" x 6", it is designed to fit common marine compartment layouts while providing dependable waste...

    $373.57
    Add to Cart
  • An image of a 22 Gallon RV Holding Tank | RV99H

    36 Gallon Marine Fresh Water Tank | B383

    This 36-gallon Ronco marine fresh water tank (B383) is built for onboard potable water storage on boats and watercraft. Measuring 32" x 32" x 9 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $408.72
    Add to Cart
  • An image of a 25 Gallon RV Holding Tank | RV98H

    36 Gallon Marine Holding Tank | B383

    This 36-gallon Ronco marine holding tank (B383) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 32" x 32" x 9 1/4", it is designed to fit common marine compartment layouts while providing dependable waste...

    $408.72
    Add to Cart
  • An image of a 29 Gallon Marine Fresh Water Tank | B423

    36 Gallon Marine Fresh Water Tank | B340

    This 36-gallon Ronco marine fresh water tank (B340) is built for onboard potable water storage on boats and watercraft. Measuring 26 1/2" x 21 1/8" x 18", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $397.67
    Add to Cart
  • An image of a 29 Gallon Marine Holding Tank | B423

    36 Gallon Marine Holding Tank | B340

    This 36-gallon Ronco marine holding tank (B340) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 26 1/2" x 21 1/8" x 18", it is designed to fit common marine compartment layouts while providing dependable...

    $397.67
    Add to Cart
  • An image of a 22 Gallon Marine Fresh Water Tank | B473

    36 Gallon Marine Fresh Water Tank | B330

    This 36-gallon Ronco marine fresh water tank (B330) is built for onboard potable water storage on boats and watercraft. Measuring 22" x 23" x 22 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $421.77
    Add to Cart
  • An image of a 22 Gallon Marine Holding Tank | B473

    36 Gallon Marine Holding Tank | B330

    This 36-gallon Ronco marine holding tank (B330) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 22" x 23" x 22 1/2", it is designed to fit common marine compartment layouts while providing dependable waste...

    $421.77
    Add to Cart
  • An image of a 135 Gallon RV Fresh Water Tank | B300

    36 Gallon Marine Fresh Water Tank | B254

    This 36-gallon Ronco marine fresh water tank (B254) is built for onboard potable water storage on boats and watercraft. Measuring 28 3/8" x 17 7/8" x 17 3/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $373.57
    Add to Cart
  • An image of a 135 Gallon Marine Fresh Water Tank | B300

    36 Gallon Marine Holding Tank | B254

    This 36-gallon Ronco marine holding tank (B254) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 28 3/8" x 17 7/8" x 17 3/4", it is designed to fit common marine compartment layouts while providing dependable...

    $373.57
    Add to Cart
  • An image of a 36 Gallon Marine Holding Tank | B428

    36 Gallon Marine Fresh Water Tank | B158

    This 36-gallon Ronco marine fresh water tank (B158) is built for onboard potable water storage on boats and watercraft. Measuring 30 1/2" x 21 1/2" x 13 3/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $373.57
    Add to Cart
  • An image of a 105 Gallon RV Fresh Water Tank | B427

    36 Gallon Marine Holding Tank | B158

    This 36-gallon Ronco marine holding tank (B158) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 30 1/2" x 21 1/2" x 13 3/4", it is designed to fit common marine compartment layouts while providing dependable...

    $373.57
    Add to Cart
  • 36 Gallon RV Water Tank W-531. Technical drawing of a polyethylene water tank designed for your rv.

    36 Gallon RV Water Tank W-531

    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 36 Gallon RV Water Tank, Part# W-531, is engineered to meet the requirements of mobile water...

    MSRP: $233.27
    $221.79
    Add to Cart
  • 36 Gallon RV Water Tank W-503. Technical drawing of a polyethylene water tank designed for your rv.

    36 Gallon RV Water Tank W-503

    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 36 Gallon RV Water Tank, Part# W-503, is engineered to meet the requirements of mobile water...

    MSRP: $220.31
    $209.47
    Add to Cart
  • 36 Gallon RV Water Tank W-469. Technical drawing of a polyethylene water tank designed for your rv.

    36 Gallon RV Water Tank W-469

    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 36 Gallon RV Water Tank, Part# W-469, is engineered to meet the requirements of mobile water...

    MSRP: $207.36
    $197.15
    Add to Cart
  • 36 Gallon RV Water Tank W-454. Technical drawing of a polyethylene water tank designed for your rv.

    36 Gallon RV Water Tank W-454

    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 36 Gallon RV Water Tank, Part# W-454, is engineered to meet the requirements of mobile water...

    MSRP: $298.07
    $283.39
    Add to Cart
  • 36 Gallon RV Water Tank W-3. Technical drawing of a polyethylene water tank designed for your rv.

    36 Gallon RV Water Tank W-3

    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 36 Gallon RV Water Tank, Part# W-3, is engineered to meet the requirements of mobile water...

    MSRP: $207.36
    $197.15
    Add to Cart
  • 36 Gallon Marine Water Tank MW-531. Technical drawing of a polyethylene water tank designed for marine vessels.

    36 Gallon Marine Water Tank MW-531

    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 36 Gallon Marine Water Tank, Part# MW-531, is engineered to meet the requirements of mobile...

    MSRP: $503.25
    $478.48
    Add to Cart
  • 36 Gallon Marine Water Tank MW-503. Technical drawing of a polyethylene water tank designed for marine vessels.

    36 Gallon Marine Water Tank MW-503

    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 36 Gallon Marine Water Tank, Part# MW-503, is engineered to meet the requirements of mobile...

    MSRP: $334.42
    $317.96
    Add to Cart
  • 36 Gallon Marine Water Tank MW-469. Technical drawing of a polyethylene water tank designed for marine vessels.

    36 Gallon Marine Water Tank MW-469

    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 36 Gallon Marine Water Tank, Part# MW-469, is engineered to meet the requirements of mobile...

    MSRP: $398.69
    $379.07
    Add to Cart
  • 36 Gallon Marine Water Tank MW-3. Technical drawing of a polyethylene water tank designed for marine vessels.

    36 Gallon Marine Water Tank MW-3

    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 36 Gallon Marine Water Tank, Part# MW-3, is engineered to meet the requirements of mobile...

    MSRP: $377.57
    $358.99
    Add to Cart
  • 36 Gallon RV Holding Tank H-616. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    36 Gallon RV Holding Tank H-616

    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 36 Gallon RV Holding Tank, Part# H-616, is engineered to meet the requirements of mobile...

    MSRP: $246.23
    $234.11
    Add to Cart