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 13 Gallon Marine Fresh Water Tank | B262

    15 Gallon Marine Fresh Water Tank | B320

    This 15-gallon Ronco marine fresh water tank (B320) is built for onboard potable water storage on boats and watercraft. Measuring 17 1/2" x 16 3/4" x 13 3/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $232.98
    Add to Cart
  • An image of a 13 Gallon Marine Holding Tank | B262

    15 Gallon Marine Holding Tank | B320

    This 15-gallon Ronco marine holding tank (B320) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 17 1/2" x 16 3/4" x 13 3/4", it is designed to fit common marine compartment layouts while providing dependable...

    $232.98
    Add to Cart
  • An image of a 22 Gallon Marine Holding Tank | B276

    15 Gallon Marine Fresh Water Tank | B264

    This 15-gallon Ronco marine fresh water tank (B264) is built for onboard potable water storage on boats and watercraft. Measuring 22" x 17" x 9 7/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $232.98
    Add to Cart
  • An image of a 7 Gallon Marine Fresh Water Tank | B275

    15 Gallon Marine Holding Tank | B264

    This 15-gallon Ronco marine holding tank (B264) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 22" x 17" x 9 7/8", it is designed to fit common marine compartment layouts while providing dependable waste...

    $232.98
    Add to Cart
  • An image of a 30 Gallon Marine Holding Tank | B190

    15 Gallon Marine Fresh Water Tank | B251

    This 15-gallon Ronco marine fresh water tank (B251) is built for onboard potable water storage on boats and watercraft. Measuring 27 1/2" x 14 3/4" x 9 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $232.98
    Add to Cart
  • An image of a 30 Gallon Marine Fresh Water Tank | B189

    15 Gallon Marine Holding Tank | B251

    This 15-gallon Ronco marine holding tank (B251) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 27 1/2" x 14 3/4" x 9 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $232.98
    Add to Cart
  • An image of a 30 Gallon Marine Fresh Water Tank | B118

    15 Gallon Marine Fresh Water Tank | B175

    This 15-gallon Ronco marine fresh water tank (B175) is built for onboard potable water storage on boats and watercraft. Measuring 20" x 13" x 13", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $232.98
    Add to Cart
  • An image of a 22 Gallon Marine Fresh Water Tank | B117

    15 Gallon Marine Holding Tank | B175

    This 15-gallon Ronco marine holding tank (B175) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 20" x 13" x 13", it is designed to fit common marine compartment layouts while providing dependable waste...

    $232.98
    Add to Cart
  • An image of a 48 Gallon Marine Fresh Water Tank | B293

    15 Gallon Marine Fresh Water Tank | B173

    This 15-gallon Ronco marine fresh water tank (B173) is built for onboard potable water storage on boats and watercraft. Measuring 21" x 17 1/2" x 13 1/4", 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 48 Gallon Marine Holding Tank | B293

    15 Gallon Marine Holding Tank | B173

    This 15-gallon Ronco marine holding tank (B173) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 21" x 17 1/2" x 13 1/4", it is designed to fit common marine compartment layouts while providing dependable...

    $246.04
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B200

    15 Gallon Marine Fresh Water Tank | B131

    This 15-gallon Ronco marine fresh water tank (B131) is built for onboard potable water storage on boats and watercraft. Measuring 20" x 15" x 12", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $232.98
    Add to Cart
  • An image of a 12 Gallon Marine Fresh Water Tank | B199

    15 Gallon Marine Holding Tank | B131

    This 15-gallon Ronco marine holding tank (B131) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 20" x 15" x 12", it is designed to fit common marine compartment layouts while providing dependable waste...

    $232.98
    Add to Cart
  • 15 Gallon RV Water Tank W-543. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank W-543

    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 15 Gallon RV Water Tank, Part# W-543, is engineered to meet the requirements of mobile water...

    MSRP: $142.56
    $135.54
    Add to Cart
  • 15 Gallon RV Water Tank W-489. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank W-489

    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 15 Gallon RV Water Tank, Part# W-489, is engineered to meet the requirements of mobile water...

    MSRP: $90.72
    $86.25
    Add to Cart
  • 15 Gallon RV Water Tank W-366. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank W-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 15 Gallon RV Water Tank, Part# W-366, is engineered to meet the requirements of mobile water...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 15 Gallon RV Water Tank W-355. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank W-355

    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 15 Gallon RV Water Tank, Part# W-355, is engineered to meet the requirements of mobile water...

    MSRP: $103.68
    $98.58
    Add to Cart
  • 15 Gallon RV Water Tank W-327. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank W-327

    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 15 Gallon RV Water Tank, Part# W-327, is engineered to meet the requirements of mobile water...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 15 Gallon RV Water Tank L-3. Technical drawing of a polyethylene water tank designed for your rv.

    15 Gallon RV Water Tank L-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 15 Gallon RV Water Tank, Part# L-3, is engineered to meet the requirements of mobile water...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 15 Gallon Marine Water Tank MW-543. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-543

    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 15 Gallon Marine Water Tank, Part# MW-543, is engineered to meet the requirements of mobile...

    MSRP: $346.52
    $329.47
    Add to Cart
  • 15 Gallon Marine Water Tank MW-489. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-489

    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 15 Gallon Marine Water Tank, Part# MW-489, is engineered to meet the requirements of mobile...

    MSRP: $185.41
    $176.28
    Add to Cart
  • 15 Gallon Marine Water Tank MW-366. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-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 15 Gallon Marine Water Tank, Part# MW-366, is engineered to meet the requirements of mobile...

    MSRP: $246.93
    $234.77
    Add to Cart
  • 15 Gallon Marine Water Tank MW-355. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-355

    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 15 Gallon Marine Water Tank, Part# MW-355, is engineered to meet the requirements of mobile...

    MSRP: $182.38
    $173.40
    Add to Cart
  • 15 Gallon Marine Water Tank MW-328. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-328

    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 15 Gallon Marine Water Tank, Part# MW-328, is engineered to meet the requirements of mobile...

    MSRP: $300.67
    $285.87
    Add to Cart
  • 15 Gallon Marine Water Tank MW-327. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-327

    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 15 Gallon Marine Water Tank, Part# MW-327, is engineered to meet the requirements of mobile...

    MSRP: $205.77
    $195.65
    Add to Cart
  • 15 Gallon Marine Water Tank ML-3. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank ML-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 15 Gallon Marine Water Tank, Part# ML-3, is engineered to meet the requirements of mobile...

    MSRP: $231.73
    $220.33
    Add to Cart
  • 15 Gallon RV Holding Tank H-236 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    15 Gallon RV Holding Tank H-236

    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 15 Gallon RV Holding Tank, Part# H-236, is engineered to meet the requirements of mobile...

    MSRP: $181.44
    $172.50
    Add to Cart
  • 15 Gallon RV Holding Tank H-229 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    15 Gallon RV Holding Tank H-229

    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 15 Gallon RV Holding Tank, Part# H-229, is engineered to meet the requirements of mobile...

    MSRP: $116.64
    $110.90
    Add to Cart
  • 15 Gallon RV Holding Tank H-131. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    15 Gallon RV Holding Tank H-131

    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 15 Gallon RV Holding Tank, Part# H-131, is engineered to meet the requirements of mobile...

    MSRP: $155.52
    $147.87
    Add to Cart
  • 15 Gallon RV Holding Tank H-79 (OR). Technical drawing of a polyethylene holding tank designed for your rv and camper.

    15 Gallon RV Holding Tank H-79 (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 15 Gallon RV Holding Tank, Part# H-79 (OR), is engineered to meet the requirements of mobile...

    MSRP: $155.52
    $147.87
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B164

    16 Gallon RV Fresh Water Tank | RVB526

    This 16-gallon Ronco RV fresh water tank (RVB526) provides reliable potable water storage for recreational vehicles. Measuring 26" x 14" x 11", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $190.80
    Add to Cart
  • An image of a 14 Gallon Marine Fresh Water Tank | B238

    16 Gallon RV Fresh Water Tank | RVB106

    This 16-gallon Ronco RV fresh water tank (RVB106) provides reliable potable water storage for recreational vehicles. Measuring 16" x 16" x 16", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $207.87
    Add to Cart