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

  • 50 Gallon RV Holding Tank H-499 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-499

    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 50 Gallon RV Holding Tank, Part# H-499, is engineered to meet the requirements of mobile...

    MSRP: $349.91
    $332.68
    Add to Cart
  • 50 Gallon RV Holding Tank H-446 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-446

    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 50 Gallon RV Holding Tank, Part# H-446, is engineered to meet the requirements of mobile...

    MSRP: $349.91
    $332.68
    Add to Cart
  • 50 Gallon RV Holding Tank H-431 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-431

    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 50 Gallon RV Holding Tank, Part# H-431, is engineered to meet the requirements of mobile...

    MSRP: $414.71
    $394.29
    Add to Cart
  • 50 Gallon RV Holding Tank H-413 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-413

    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 50 Gallon RV Holding Tank, Part# H-413, is engineered to meet the requirements of mobile...

    MSRP: $323.99
    $308.04
    Add to Cart
  • 50 Gallon RV Holding Tank H-374 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-374 [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 50 Gallon RV Holding Tank, Part# H-374 [OR], is engineered to meet the requirements of mobile...

    MSRP: $349.91
    $332.68
    Add to Cart
  • 50 Gallon RV Holding Tank H-371 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-371

    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 50 Gallon RV Holding Tank, Part# H-371, is engineered to meet the requirements of mobile...

    MSRP: $311.03
    $295.72
    Add to Cart
  • 50 Gallon RV Holding Tank H-361 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    50 Gallon RV Holding Tank H-361 [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 50 Gallon RV Holding Tank, Part# H-361 [OR], is engineered to meet the requirements of mobile...

    MSRP: $285.11
    $271.08
    Add to Cart
  • 51 Gallon RV Water Tank W-532. Technical drawing of a polyethylene water tank designed for your rv.

    51 Gallon RV Water Tank W-532

    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 51 Gallon RV Water Tank, Part# W-532, is engineered to meet the requirements of mobile water...

    MSRP: $298.07
    $283.39
    Add to Cart
  • 51 Gallon Marine Water Tank MW-532. Technical drawing of a polyethylene water tank designed for marine vessels.

    51 Gallon Marine Water Tank MW-532

    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 51 Gallon Marine Water Tank, Part# MW-532, is engineered to meet the requirements of mobile...

    MSRP: $783.22
    $744.66
    Add to Cart
  • 51 Gallon RV Holding Tank H-655. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    51 Gallon RV Holding Tank H-655

    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 51 Gallon RV Holding Tank, Part# H-655, is engineered to meet the requirements of mobile...

    MSRP: $401.75
    $381.97
    Add to Cart
  • 51 Gallon RV Holding Tank H-528 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    51 Gallon RV Holding Tank H-528

    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 51 Gallon RV Holding Tank, Part# H-528, is engineered to meet the requirements of mobile...

    MSRP: $466.54
    $443.58
    Add to Cart
  • 51 Gallon RV Holding Tank H-437 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    51 Gallon RV Holding Tank H-437 [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 51 Gallon RV Holding Tank, Part# H-437 [OR], is engineered to meet the requirements of mobile...

    MSRP: $336.95
    $320.36
    Add to Cart
  • 51 Gallon RV Holding Tank H-257 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    51 Gallon RV Holding Tank H-257

    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 51 Gallon RV Holding Tank, Part# H-257, is engineered to meet the requirements of mobile...

    MSRP: $233.27
    $221.79
    Add to Cart
  • An image of a 11 Gallon Marine Fresh Water Tank | BOAT16W

    52 Gallon RV Fresh Water Tank | RVB315

    This 52-gallon Ronco RV fresh water tank (RVB315) provides reliable potable water storage for recreational vehicles. Measuring 30 1/2" x 24 3/8" x 17 3/8", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $354.50
    Add to Cart
  • An image of a 30 Gallon Marine Holding Tank | B481

    52 Gallon RV Fresh Water Tank | RVB295

    This 52-gallon Ronco RV fresh water tank (RVB295) provides reliable potable water storage for recreational vehicles. Measuring 28" x 23" x 21", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $471.99
    Add to Cart
  • An image of a 50 Gallon RV Fresh Water Tank | RVB465

    52 Gallon RV Fresh Water Tank | RV8W

    This 52-gallon Ronco RV fresh water tank (RV8W) provides reliable potable water storage for recreational vehicles. Measuring 60 1/4" x 20 1/8" x 11", 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 42 Gallon Marine Holding Tank | B510

    52 Gallon Marine Fresh Water Tank | BOAT48W

    This 52-gallon Ronco marine fresh water tank (BOAT48W) is built for onboard potable water storage on boats and watercraft. Measuring 40" x 24" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $456.93
    Add to Cart
  • An image of a 60 Gallon RV Fresh Water Tank | B508

    52 Gallon Marine Holding Tank | BOAT48W

    This 52-gallon Ronco marine holding tank (BOAT48W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 40" x 24" x 14", it is designed to fit common marine compartment layouts while providing dependable waste...

    $456.93
    Add to Cart
  • An image of a 12 Gallon RV Fresh Water Tank | RVB105

    52 Gallon Marine Fresh Water Tank | B422

    This 52-gallon Ronco marine fresh water tank (B422) is built for onboard potable water storage on boats and watercraft. Measuring 65 1/2" x 32" x 12 1/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $632.67
    Add to Cart
  • An image of a 48 Gallon RV Fresh Water Tank | RV9W

    52 Gallon Marine Holding Tank | B422

    This 52-gallon Ronco marine holding tank (B422) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 65 1/2" x 32" x 12 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $632.67
    Add to Cart
  • An image of a 7 Gallon Marine Fresh Water Tank | B344

    52 Gallon Marine Fresh Water Tank | B333

    This 52-gallon Ronco marine fresh water tank (B333) is built for onboard potable water storage on boats and watercraft. Measuring 56 1/2" x 18 1/2" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $538.27
    Add to Cart
  • An image of a 7 Gallon Marine Holding Tank | B344

    52 Gallon Marine Holding Tank | B333

    This 52-gallon Ronco marine holding tank (B333) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 56 1/2" x 18 1/2" x 14", it is designed to fit common marine compartment layouts while providing dependable...

    $538.27
    Add to Cart
  • An image of a 11 Gallon Marine Holding Tank | BOAT16W

    52 Gallon Marine Fresh Water Tank | B315

    This 52-gallon Ronco marine fresh water tank (B315) is built for onboard potable water storage on boats and watercraft. Measuring 30 1/2" x 24 3/8" x 17 3/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $491.07
    Add to Cart
  • An image of a 11 Gallon Marine Fresh Water Tank | BOAT14W

    52 Gallon Marine Holding Tank | B315

    This 52-gallon Ronco marine holding tank (B315) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 30 1/2" x 24 3/8" x 17 3/8", it is designed to fit common marine compartment layouts while providing dependable...

    $491.07
    Add to Cart
  • An image of a 19 Gallon Marine Fresh Water Tank | B480

    52 Gallon Marine Fresh Water Tank | B295

    This 52-gallon Ronco marine fresh water tank (B295) is built for onboard potable water storage on boats and watercraft. Measuring 28" x 23" x 21", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $491.07
    Add to Cart
  • An image of a 19 Gallon Marine Holding Tank | B480

    52 Gallon Marine Holding Tank | B295

    This 52-gallon Ronco marine holding tank (B295) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 28" x 23" x 21", it is designed to fit common marine compartment layouts while providing dependable waste...

    $491.07
    Add to Cart
  • 52 Gallon RV Water Tank W-212. Technical drawing of a polyethylene water tank designed for your rv.

    52 Gallon RV Water Tank W-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 52 Gallon RV Water Tank, Part# W-212, is engineered to meet the requirements of mobile water...

    MSRP: $259.19
    $246.44
    Add to Cart
  • 52 Gallon Marine Water Tank MW-212. Technical drawing of a polyethylene water tank designed for marine vessels.

    52 Gallon Marine Water Tank MW-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 52 Gallon Marine Water Tank, Part# MW-212, is engineered to meet the requirements of mobile...

    MSRP: $490.53
    $466.37
    Add to Cart
  • 52 Gallon RV Holding Tank H-591. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    52 Gallon RV Holding Tank H-591

    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 52 Gallon RV Holding Tank, Part# H-591, is engineered to meet the requirements of mobile...

    MSRP: $596.14
    $566.79
    Add to Cart
  • 52 Gallon RV Holding Tank H-395 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    52 Gallon RV Holding Tank H-395 [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 52 Gallon RV Holding Tank, Part# H-395 [OR], is engineered to meet the requirements of mobile...

    MSRP: $401.75
    $381.97
    Add to Cart
  • 52 Gallon RV Holding Tank H-394 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    52 Gallon RV Holding Tank H-394 [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 52 Gallon RV Holding Tank, Part# H-394 [OR], is engineered to meet the requirements of mobile...

    MSRP: $401.75
    $381.97
    Add to Cart