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

  • 16 Gallon RV Water Tank W-559. Technical drawing of a polyethylene water tank designed for your rv.

    16 Gallon RV Water Tank W-559

    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 16 Gallon RV Water Tank, Part# W-559, is engineered to meet the requirements of mobile water...

    MSRP: $168.48
    $160.19
    Add to Cart
  • 16 Gallon RV Water Tank W-551. Technical drawing of a polyethylene water tank designed for your rv.

    16 Gallon RV Water Tank W-551

    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 16 Gallon RV Water Tank, Part# W-551, is engineered to meet the requirements of mobile water...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 16 Gallon RV Water Tank W-492. Technical drawing of a polyethylene water tank designed for your rv.

    16 Gallon RV Water Tank W-492

    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 16 Gallon RV Water Tank, Part# W-492, is engineered to meet the requirements of mobile water...

    MSRP: $259.19
    $246.44
    Add to Cart
  • 16 Gallon RV Water Tank W-282. Technical drawing of a polyethylene water tank designed for your rv.

    16 Gallon RV Water Tank W-282

    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 16 Gallon RV Water Tank, Part# W-282, is engineered to meet the requirements of mobile water...

    MSRP: $129.60
    $123.22
    Add to Cart
  • 16 Gallon Marine Water Tank MW-559. Technical drawing of a polyethylene water tank designed for marine vessels.

    16 Gallon Marine Water Tank MW-559

    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 16 Gallon Marine Water Tank, Part# MW-559, is engineered to meet the requirements of mobile...

    MSRP: $232.17
    $220.74
    Add to Cart
  • 16 Gallon Marine Water Tank MW-551. Technical drawing of a polyethylene water tank designed for marine vessels.

    16 Gallon Marine Water Tank MW-551

    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 16 Gallon Marine Water Tank, Part# MW-551, is engineered to meet the requirements of mobile...

    MSRP: $258.66
    $245.92
    Add to Cart
  • 16 Gallon Marine Water Tank MW-492. Technical drawing of a polyethylene water tank designed for marine vessels.

    16 Gallon Marine Water Tank MW-492

    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 16 Gallon Marine Water Tank, Part# MW-492, is engineered to meet the requirements of mobile...

    MSRP: $223.33
    $212.33
    Add to Cart
  • 16 Gallon Marine Water Tank MW-27. Technical drawing of a polyethylene water tank designed for marine vessels.

    16 Gallon Marine Water Tank MW-27

    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 16 Gallon Marine Water Tank, Part# MW-27, is engineered to meet the requirements of mobile...

    MSRP: $192.82
    $183.33
    Add to Cart
  • 16 Gallon RV Holding Tank H-589 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    16 Gallon RV Holding Tank H-589

    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 16 Gallon RV Holding Tank, Part# H-589, is engineered to meet the requirements of mobile...

    MSRP: $168.48
    $160.19
    Add to Cart
  • 16 Gallon RV Holding Tank H-379 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    16 Gallon RV Holding Tank H-379

    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 16 Gallon RV Holding Tank, Part# H-379, is engineered to meet the requirements of mobile...

    MSRP: $103.68
    $98.58
    Add to Cart
  • 16 Gallon RV Holding Tank H-307 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    16 Gallon RV Holding Tank H-307

    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 16 Gallon RV Holding Tank, Part# H-307, is engineered to meet the requirements of mobile...

    MSRP: $220.31
    $209.47
    Add to Cart
  • 16 Gallon RV Holding Tank H-274 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    16 Gallon RV Holding Tank H-274

    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 16 Gallon RV Holding Tank, Part# H-274, is engineered to meet the requirements of mobile...

    MSRP: $194.40
    $184.82
    Add to Cart
  • 16 Gallon RV Holding Tank H-271 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    16 Gallon RV Holding Tank H-271

    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 16 Gallon RV Holding Tank, Part# H-271, is engineered to meet the requirements of mobile...

    MSRP: $181.44
    $172.50
    Add to Cart
  • An image of a 18 Gallon Marine Holding Tank | B232

    17 Gallon RV Fresh Water Tank | RVB359

    This 17-gallon Ronco RV fresh water tank (RVB359) provides reliable potable water storage for recreational vehicles. Measuring 19 3/4" x 15 3/4" x 14", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $204.86
    Add to Cart
  • An image of a 40 Gallon Marine Fresh Water Tank | B305

    17 Gallon RV Fresh Water Tank | RVB325

    This 17-gallon Ronco RV fresh water tank (RVB325) provides reliable potable water storage for recreational vehicles. Measuring 19 1/2" x 18" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $230.97
    Add to Cart
  • An image of a 25 Gallon Marine Fresh Water Tank | B194

    17 Gallon RV Holding Tank | RV94H

    This 17-gallon Ronco RV holding tank (RV94H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 54" x 15" x 9", it fits common RV underbelly and compartment configurations while providing reliable waste containment...

    $281.18
    Add to Cart
  • An image of a 28 Gallon Marine Holding Tank | B413

    17 Gallon RV Fresh Water Tank | RV36W

    This 17-gallon Ronco RV fresh water tank (RV36W) provides reliable potable water storage for recreational vehicles. Measuring 23" x 21" x 9", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $250.05
    Add to Cart
  • An image of a 28 Gallon Marine Fresh Water Tank | B413

    17 Gallon RV Holding Tank | RV2H

    This 17-gallon Ronco RV holding tank (RV2H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 39" x 21" x 13", it fits common RV underbelly and compartment configurations while providing reliable waste containment...

    $292.23
    Add to Cart
  • An image of a 138 Gallon PE Ronco White Rectangular Open Top Tank | 40X18X48PE

    17 Gallon Marine Fresh Water Tank | BOAT27W

    This 17-gallon Ronco marine fresh water tank (BOAT27W) is built for onboard potable water storage on boats and watercraft. Measuring 32" x 12" x 12", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $269.13
    Add to Cart
  • An image of a 3 Gallon PP Ronco White Cylindrical Open Top Tank | 3PP

    17 Gallon Marine Holding Tank | BOAT27W

    This 17-gallon Ronco marine holding tank (BOAT27W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 32" x 12" x 12", it is designed to fit common marine compartment layouts while providing dependable waste...

    $269.13
    Add to Cart
  • An image of a 40 Gallon Marine Holding Tank | B222

    17 Gallon Marine Fresh Water Tank | BOAT20W

    This 17-gallon Ronco marine fresh water tank (BOAT20W) is built for onboard potable water storage on boats and watercraft. Measuring 38" x 15 1/2" x 8 1/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $269.13
    Add to Cart
  • An image of a 40 Gallon Marine Fresh Water Tank | B221

    17 Gallon Marine Holding Tank | BOAT20W

    This 17-gallon Ronco marine holding tank (BOAT20W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 38" x 15 1/2" x 8 1/8", it is designed to fit common marine compartment layouts while providing dependable...

    $269.13
    Add to Cart
  • An image of a 65 Gallon Marine Holding Tank | B297

    17 Gallon Marine Fresh Water Tank | B462

    This 17-gallon Ronco marine fresh water tank (B462) is built for onboard potable water storage on boats and watercraft. Measuring 37 1/4" x 17 3/4" x 17 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $281.18
    Add to Cart
  • An image of a 70 Gallon RV Fresh Water Tank | B296

    17 Gallon Marine Holding Tank | B462

    This 17-gallon Ronco marine holding tank (B462) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 37 1/4" x 17 3/4" x 17 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $281.18
    Add to Cart
  • An image of a 20 Gallon Marine Fresh Water Tank | B231

    17 Gallon Marine Fresh Water Tank | B359

    This 17-gallon Ronco marine fresh water tank (B359) is built for onboard potable water storage on boats and watercraft. Measuring 19 3/4" x 15 3/4" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $256.08
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B231

    17 Gallon Marine Holding Tank | B359

    This 17-gallon Ronco marine holding tank (B359) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 19 3/4" x 15 3/4" x 14", it is designed to fit common marine compartment layouts while providing dependable...

    $256.08
    Add to Cart
  • An image of a 40 Gallon Marine Holding Tank | B305

    17 Gallon Marine Fresh Water Tank | B325

    This 17-gallon Ronco marine fresh water tank (B325) is built for onboard potable water storage on boats and watercraft. Measuring 19 1/2" x 18" x 12", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $256.08
    Add to Cart
  • An image of a 9 Gallon Marine Fresh Water Tank | B304

    17 Gallon Marine Holding Tank | B325

    This 17-gallon Ronco marine holding tank (B325) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 19 1/2" x 18" x 12", it is designed to fit common marine compartment layouts while providing dependable waste...

    $256.08
    Add to Cart
  • An image of a 10 Gallon Marine Fresh Water Tank | B278

    17 Gallon Marine Fresh Water Tank | B226

    This 17-gallon Ronco marine fresh water tank (B226) is built for onboard potable water storage on boats and watercraft. Measuring 20 1/8" x 17" x 13 7/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $246.04
    Add to Cart
  • An image of a 10 Gallon Marine Holding Tank | B278

    17 Gallon Marine Holding Tank | B226

    This 17-gallon Ronco marine holding tank (B226) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 20 1/8" x 17" x 13 7/8", it is designed to fit common marine compartment layouts while providing dependable...

    $246.04
    Add to Cart
  • An image of a 30 Gallon Marine Fresh Water Tank | B202

    17 Gallon Marine Fresh Water Tank | B123

    This 17-gallon Ronco marine fresh water tank (B123) is built for onboard potable water storage on boats and watercraft. Measuring 30" x 15" x 13 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $268.13
    Add to Cart
  • An image of a 30 Gallon Marine Holding Tank | B202

    17 Gallon Marine Holding Tank | B123

    This 17-gallon Ronco marine holding tank (B123) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 30" x 15" x 13 1/2", it is designed to fit common marine compartment layouts while providing dependable waste...

    $268.13
    Add to Cart