Water Storage

3 Options for a 20 Gallon Water Storage Tank in 2026

A white tank on a concrete slab beside a fence

The short answer

Use a potable RV tank for a plumbed setup, or split the same supply into jugs for a home emergency.

Last updated October 2026

Contents7

Our top 3 picks

  1. 1Best compact RV tank
    ICON WT2454 20-Gallon Fresh Water Tank
    ICON WT2454 20-Gallon Fresh Water TankView at ICON TechnologiesRead our analysis
  2. 2Best narrow RV tank
    Class A Customs T-2000 20-Gallon Fresh / Gray Water Tank
    Class A Customs T-2000 20-Gallon Fresh / Gray Water TankView at Class A CustomsRead our analysis
  3. 3Best home alternative
    Ready Store 20-Gallon Stackable Water Container Kit (4 x 5-Gallon)
    Ready Store 20-Gallon Stackable Water Container Kit (4 x 5-Gallon)View at Ready StoreRead our analysis

A 20 gallon water storage tank is a useful small reserve for a household or RV. At the CDC minimum of one gallon per person per day, 20 gallons covers four people for five days, by calculation. Choose a tank listed for potable water if you will drink from it. For home storage, several smaller jugs may be easier to fill and rotate than one plumbed tank.

#1. ICON WT2454 20-Gallon Fresh Water Tank: best for a compact RV space

The WT2454 measures 24 by 18 by 12 inches and holds 20 gallons. Choose between the tank-only option and the configuration with three 1/2-inch FPT fittings and a 1.25-inch fill fitting. Measure the available space and leave room to reach the ports for installation and service.

#2. Class A Customs T-2000 20-Gallon Fresh / Gray Water Tank: best for a long, narrow bay

The different shape is the reason to compare it with the ICON WT2454 20-Gallon Fresh Water Tank. Both hold the same stated amount, but fit different spaces. Leave room around the ports. Check what you need to add for filling, venting and drawing water before buying a bare tank.

#3. Ready Store 20-Gallon Stackable Water Container Kit (4 x 5-Gallon): best portable 20-gallon alternative

This set makes sense when you want the total supply without installing plumbing. You can rotate part of the stash while keeping the rest sealed. Check that each full jug is manageable for the person who will use it; a handle does not make a heavy load light.

How many days does a 20 gallon water storage tank cover

These are calculated from the CDC's one-gallon daily minimum, assuming the whole 20 gallons is usable:

People Days covered
1 20
2 10
3 About 6.7
4 5
5 4

This is an emergency allowance, not a normal showering or RV-use budget. The CDC advises extra water for pets, pregnant people, illness and hot climates. Deduct that extra demand before calling the tank enough for your trip or outage. Our emergency water planning guide helps set a household target.

Factors to consider when choosing a small tank

We used the CDC's storage guidance and each listing's material, shape and fitting claims. We did not test these by hand. Details come from each listing, so check the current page and manual before you buy.

Start with drinking-water use. A utility tank for a garden has a different job from a potable fresh-water tank. Check the exact model and any hose or tap that will touch the drinking water.

Plan to fill, clean and drain the tank without taking apart the room. The CDC says to sanitize containers before filling. A service route matters as much as a neat fit. Put valves where you can reach them and inspect connections before relying on the stash.

Home storage or RV use

Keep a home reserve where you can get to it during a power cut. The CDC calls for cool storage, shade and separation from toxic chemicals. Label home-filled water with its fill date and replace it every six months under the same guidance. See long-term water storage for the full routine.

An RV tank also needs to fit the vehicle's support and water system. Water alone adds about 167 pounds at this capacity, calculated from USGS density data. Include the tank and other loads when checking the vehicle's limits. A fixed tank is useful for utility work only when the intended liquid matches its listing.

Verdict: 20 gallon water storage tank

A potable 20 gallon water storage tank fits a small fixed system; jugs fit a stash you want to split and carry. Measure the space and work out demand first. Return to the rain water barrel guide for storage and treatment options.

Questions people also ask

How long does 20 gallons last four people?

Five days at the CDC minimum of one gallon per person per day, before extra needs for pets, heat or illness. The calculation and source are below.

Can I connect an RV tank directly to a pressure supply?

Follow each maker's installation instructions. Class A Customs says the T-2000 must be vented and must not be pressurized. Check ICON's filling and venting instructions for the WT2454 rather than assuming a pressure rating.