Best RV Grey Water Holding Tanks for Replacement and Upgrades
The best RV grey water holding tank depends on available installation space, required capacity, and outlet size. The classAcustoms 32-gallon tank is best for buyers who need substantial grey-water storage with a 1.5-inch outlet; the RecPro tank suits a larger installation with its listed dimensions and included fittings. Smaller options include a 13-gallon classAcustoms tank and a 16-gallon waste tank whose listing says it can be used for grey water. Check dimensions and plumbing before choosing.
| Product | Listed capacity | Best suited for |
|---|---|---|
| classAcustoms WT-3232 | 32 gallons | Higher capacity with a 1.5-inch outlet |
| RecPro 50 Gallon RV Holding Tank | 48.5 gallons actual | Large, dimension-specific installations |
| Custom Roto-Molding H85 | 50 gallons | Buyers seeking a basic large tank |
| classAcustoms 24394 | 13 gallons | Compact grey-water use |
| classAcustoms WT-1653 | 16 gallons | Small waste-water installations |
classAcustoms WT-3232 32-Gallon Grey Tank
Best for: RV owners who need a relatively large replacement tank with a 1.5-inch outlet. The WT-3232 is made from medium-density polyethylene and is listed for waste or grey-water use, not drinking water. Its 32-gallon capacity offers more storage than the 13- and 16-gallon options in this comparison.
The outlet is a fixed 1.5-inch ABS female pipe fitting. The listing says the tank comes with the outlet only; buyers must plan the inlet, vent, and related hardware. A vent is required, and the tank must not be pressurized. Choose this tank if its dimensions and outlet position suit the installation; avoid it if you need a tank with fittings or an inlet already installed.
RecPro 50-Gallon RV Holding Tank
Best for: Buyers replacing a larger tank where the stated footprint matches their RV. RecPro lists dimensions of 53 by 27 by 10.5 inches and an actual capacity of 48.5 gallons. The tank is made from polyethylene, and the product description notes a connection clamp on the port and compatibility with a RecPro tank installation kit.
Its substantial dimensions make measuring the compartment especially important. The listing describes a precise fit for RV dimensions but does not establish that it fits every RV. Confirm port placement and installation requirements before purchase. Choose this model when its size and connection setup match the existing system; avoid it for a tight compartment or a small-capacity replacement.
Custom Roto-Molding H85 50-Gallon Tank
Best for: Buyers looking for a 50-gallon holding tank and able to confirm the installation details separately. The supplied product information identifies the H85 as a 50-gallon waste-water holding tank from Custom Roto-Molding.
The available features do not specify dimensions, outlet size, material, or included fittings. Those details can determine whether a tank works as a grey-water replacement, so verify them with the seller and compare them with the RV’s existing setup before ordering. This is a capacity-led option, not the best choice if you need detailed fitting information in the product description.
classAcustoms 24394 Compact Grey Tank
Best for: RV owners who need a smaller grey-water tank and have a compatible installation space. The listing gives dimensions of 24 by 39 by 4 inches, a 13-gallon capacity, and one-piece polyethylene construction. Its features specify grey-water use only.
There is a naming inconsistency: the product title includes “Black Tank Only,” while the feature details say “Grey Gray Water use Only.” Confirm the intended use and connection details with the seller before purchase. Its listed dimensions are useful for comparing space, but the supplied features do not state outlet specifications.
classAcustoms WT-1653 16-Gallon Waste Tank
Best for: Buyers who need a small tank and can work with a 3-inch ABS female pipe outlet. The product title identifies it as a black-water tank, while the features say it can be used for waste or grey water. It is made from medium-density polyethylene and has a listed capacity of 16 gallons.
The tank includes the outlet only; inlet and vent placement, installation hardware, and additional piping are not included. A vent is required, and the tank must not be pressurized. Because the title emphasizes black water, confirm that it suits your grey-water application before selecting it.
Buying Guide: How To Choose An RV Grey Water Tank
What capacity do you need?
Compare the replacement tank’s capacity with your current tank and typical water use. The options here range from 13 to 50 gallons, but a larger tank is useful only if it fits the available space and can connect to the plumbing. A small tank may suit compact installations; higher-capacity models can provide more storage between dump stops.
Will the tank fit the compartment?
Measure the available length, width, and height, and account for clearance around fittings and mounting points. Compare those measurements with the product specifications. Do not assume a tank is a direct replacement based on capacity alone; shape, outlet location, and inlet placement also matter.
Which outlet and fittings are required?
Check the outlet diameter and fitting type against the RV plumbing. Some tanks list an outlet but do not include a dump valve, inlet, vent, or installation hardware. Plan for any required piping and confirm how the dump valve connects. Follow the manufacturer’s installation instructions, including venting requirements.
Is a grey-water-only tank important?
Listings can use black-water, grey-water, or general waste-tank wording inconsistently. Verify that the tank is appropriate for your intended waste-water use. Never use a tank labeled for waste or grey water to store drinking water.
Frequently Asked Questions
Can a black-water tank be used for grey water?
Some listings state that a waste tank can serve grey-water use, while others specify black-water use only. Check the manufacturer’s intended use and confirm any conflicting product details before buying.
Does a replacement grey-water tank include a dump valve?
Not necessarily. The classAcustoms tank descriptions state that additional piping and dump valves are not included. Check the product’s included components before planning installation.
Does an RV holding tank need a vent?
The classAcustoms waste-tank listings state that the tank must be vented to allow air in and out during use. Follow the instructions for the specific tank and installation.
How do I confirm tank compatibility?
Compare the tank’s dimensions, capacity, outlet size, and fitting locations with the existing installation. Ask the seller to clarify missing specifications or inconsistent use descriptions before ordering.