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Quick answer from a licensed plumber: A tank’s gallon size is not the water you get. Red Lion’s rule: count fixtures (1 gpm each), multiply by 3, then go to the next larger tank. That lands on the RL34A (10.8 gallons of drawdown at 30/50) for Red Lion’s example house of 8 fixtures and the RL20A (7.2) for a smaller system. On September 28, 2026, these were the only well tanks we found sold by Amazon itself; Amtrol, Goulds and Water Worker tanks were third-party only, so they are compared but not linked.
Our pick for a one- or two-bath house: the Red Lion RL34A. Check the Red Lion RL34A on Amazon
A pressure tank keeps the pump from starting every time you open a tap. It holds pressurized water between pump cycles, and the number that matters is not its gallon size but its drawdown: the water you can use before the pump restarts. The catch with this guide is what we can link. On September 28, 2026, the Red Lion tanks were the only well tanks we found sold by Amazon itself. Every Amtrol, Goulds and Water Worker well tank we checked was sold by an outside seller, so those are compared below from the makers’ documents but not linked.
Red Lion Well Tanks Compared
| Model | Shape | Gallons | Drawdown at 30/50 (gal) | Fixtures (Red Lion) | Shortest pump run, minutes (our arithmetic) | Amazon, September 28, 2026 |
|---|---|---|---|---|---|---|
| RL2A | Inline | 2.0 | 0.7 | – | n/a | Sold by Amazon |
| RL4A | Inline | 4.5 | 1.5 | – | n/a | Sold by Amazon |
| RL6AH | Horizontal | 6.0 | 1.9 | 1 | 1.9 | Not linked: listing not confirmed on the check date |
| RL14A | Vertical | 14.0 | 4.9 | 4 | 1.2 | Low stock on the check date, not linked |
| RL20A | Vertical | 20.0 | 7.2 | 6 | 1.2 | Sold by Amazon |
| RL34A | Vertical | 34.0 | 10.8 | 11 | 1.0 | Sold by Amazon |
| RL44A | Vertical | 44.0 | 12.7 | 14 | 0.9 | Ships in 1 to 4 weeks, not linked |
| RL81A | Vertical | 81.0 | 27.6 | 27 | 1.0 | No Amazon listing found, not linked |
Gallons, drawdown and fixtures are from Red Lion’s product page. Run minutes divide the drawdown by a pump flow equal to the fixture count, which is how Red Lion’s guide pairs them: RL20A, 7.2 gallons at 6 gpm is 1.2 minutes. That is the run time with no water in use; while a tap is open, the pump runs longer. Red Lion also lists a 14-gallon horizontal RL14AH, which we did not check. The 2-gallon RL2A and 4.5-gallon RL4A carry no fixture rating from Red Lion and are too small to serve a house on their own. The Amazon column is what the listing showed on the check date; the four tanks we link (RL2A, RL4A, RL20A and RL34A) were in stock and sold by Amazon, and the four unlinked sizes show the reason.
Red Lion RL34A 34-Gallon Vertical Well Tank
34 gal · 10.8 gal drawdown at 30/50 (Red Lion) · rated for 11 fixtures · 1-inch FNPT elbow connection, 304 stainless steel · NSF/ANSI/CAN 61 and 372 · 5-year limited warranty · carton 17.7 x 17.7 x 41.7 in, shipping weight 51.1 lb
Red Lion’s sizing guide says to take the system’s flow in gallons per minute (one gpm per fixture, which it also uses to size the pump), multiply by 3 and go to the next larger tank. Its own example is a house with one full bathroom, a kitchen sink, a basement sink, an outside faucet, a washer and a dishwasher: 8 fixtures, 8 gpm, 24 gallons, so the RL34A. Red Lion rates the RL34A for 11 fixtures and lists 10.8 gallons of drawdown at 30/50. At 11 gpm the pump runs at least about 1 minute per cycle, and at the example house’s 8 gpm about 1.35 minutes (our arithmetic). For comparison, Amtrol lists its 34-gallon WX-205 at 10.5 gallons of drawdown at 30/50. A house with two full baths, a kitchen sink, dishwasher, washer and two hose bibs counts about 11 fixtures (our arithmetic), which is the RL34A’s rating.
Red Lion says the tank leaves the factory pre-charged to 20 psi, so the air pressure has to be set before it goes in: 2 psi below the switch cut-in, which is 28 psi on a 30/50 switch. The manual also calls for a 75 psi safety relief valve and says not to use the tank with water that carries sand or clay, which can damage the diaphragm and void the warranty. If you need more capacity than one tank gives, Red Lion says its tanks can be installed in series or in parallel.
- Sold and shipped by Amazon
- 10.8 gal drawdown at 30/50, close to the Amtrol 34-gallon figure (10.5)
- Butyl rubber diaphragm and polypropylene liner; NSF/ANSI/CAN 61 and 372, per Red Lion
- 5-year limited warranty, per the Red Lion manual
- Red Lion’s manual does not print a maximum pressure or temperature; it says they are marked on the tank
- Red Lion prints drawdown only at 30/50, so there is no maker figure for 40/60
- Ships at 20 psi and must be adjusted before installation
- Red Lion lists the shipping weight at 51.1 lb
Verdict: The size Red Lion’s own guide lands on for its example one-bathroom house. For more than 11 fixtures, or a pump over 3/4 hp, step up to the RL44A or larger (not in stock at Amazon on the check date), or pipe two tanks together, which Red Lion allows.
Red Lion RL20A 20-Gallon Vertical Well Tank
20 gal · 7.2 gal drawdown at 30/50 (Red Lion) · rated for 6 fixtures · 1-inch FNPT elbow connection, 304 stainless steel · NSF/ANSI/CAN 61 and 372 · 5-year limited warranty · carton 17.7 x 17.7 x 27.6 in, shipping weight 32.2 lb
The RL20A suits a system of about 6 fixtures (6 gpm) or less, which is where Red Lion’s rule (6 x 3 = 18 gallons, next size up is 20) puts it. Red Lion rates it at 7.2 gallons of drawdown at 30/50, so a pump moving 6 gpm runs at least about 1.2 minutes per cycle (our arithmetic). Amtrol, Goulds and Flexcon list 20-gallon tanks at 6.1 to 6.8 gallons, so the RL20A figure is the highest of the four. The table further down has them side by side. Red Lion prints no test method, so treat every one of these as a maker rating.
Red Lion prints drawdown only at 30/50. Other makers show less water at a higher setting: Amtrol lists its 20-gallon WX-202 at 6.2 gallons at 30/50 and 5.4 at 40/60. If you run a 40/60 switch, expect less than 7.2 gallons from any 20-gallon tank and lean toward the RL34A. Set the pre-charge to 28 psi for 30/50 or 38 psi for 40/60, always with the tank empty and the pump off.
- Sold and shipped by Amazon
- Shorter than the RL34A: carton 27.6 in tall against 41.7 in
- Red Lion’s 7.2-gallon drawdown rating is the highest of the four 20-gallon tanks compared here (see the note under that table)
- NSF/ANSI/CAN 61 and 372, per Red Lion
- Rated for only 6 fixtures
- A 40/60 switch cuts the usable water and Red Lion gives no figure for it
- Ships at 20 psi and must be adjusted before installation
- Maximum pressure and temperature are on the tank, not in the manual
Verdict: Right for a small house or a low-flow pump. If your system is over about 6 fixtures, or you run 40/60, step up to the RL34A.
I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.
Which Size for Which Pump
Red Lion’s guide counts 1 gpm for each fixture in the house, including every faucet, toilet and water-using appliance but not treatment equipment, and says the pump’s gpm must equal that count. Then it multiplies by 3 and goes to the next larger tank; for a single fixture its table lists the 6-gallon horizontal RL6AH (1.9 gallons of drawdown), and the Amazon listing says it comes with a bracket and stand so a small jet pump can sit on top. We did not link it: we could not confirm that listing on the check date. Our arithmetic on that rule, against the sizes Red Lion makes:
| System flow (fixtures x 1 gpm) | Gallons needed (gpm x 3) | Red Lion size |
|---|---|---|
| 4 | 12 | RL14A |
| 6 | 18 | RL20A |
| 8 | 24 | RL34A |
| 11 | 33 | RL34A |
| 14 | 42 | RL44A |
| 27 | 81 | RL81A |
Two cautions. Amtrol’s card uses a longer run time for pumps over 3/4 hp: it wants two minutes, not one, so a pump above 3/4 hp may call for a larger tank than this rule gives. And every figure here is for a 30/50 switch. If you run 40/60, read our well pressure switch 30/50 vs 40/60 guide and the well pressure tank size chart for how much less water a tank gives. If your pump already makes more than your fixture count, use the pump’s flow instead (our advice: the tank has to absorb what the pump delivers); it is on the pump label. If you are still choosing a pump, see our submersible well pump picks or shallow well pump picks.
The Same 20 Gallons, Four Makers
Tanks with the same gallon size do not deliver the same drawdown. Here is the 20-gallon class from four makers, at 30/50, from each maker’s own table.
| Tank | Listed gallons | Drawdown at 30/50 (gal) | Max working pressure | Warranty | Amazon, September 28, 2026 |
|---|---|---|---|---|---|
| Red Lion RL20A | 20.0 | 7.2 | Marked on the tank; not in the manual | 5 years | Sold by Amazon |
| Amtrol Well-X-Trol WX-202 | 20.0 | 6.2 | 150 psig | 7 years (WX models) | Outside sellers only |
| Goulds Hydro-Pro V60 | 19.9 | 6.1 | 125 psi | 5 years | Outside sellers only |
| Flexcon Well-Rite WR 60 | 20 | 6.8 | 125 psi | 5 years | Not found in our searches |
As a share of listed volume (our arithmetic), that is about 36 percent for Red Lion, 34 for Flexcon and 31 for Amtrol and Goulds. At 30/50, the gas law caps drawdown at about 31 percent of a tank’s internal volume (our arithmetic). Amtrol and Goulds sit right at that cap. Red Lion and Flexcon print more than a true 20-gallon vessel can deliver, so their gallon label is probably not the full internal volume; the RL20A is also wider, 17 inches against 15 for the WX-202, per the Amazon listing and Amtrol’s card. Red Lion prints no test method, and Amtrol notes that drawdown “can be affected by various ambient and system conditions, including temperature and pressure.” That is why the drawdown column matters more than the gallon label. Plan with the conservative figure if the pump is near the limit of the tank. On paper, the Amtrol WX-202 has the stronger documents: a 7-year warranty and a printed 150 psig rating, against 5 years and a rating printed only on the tank for Red Lion. If you can buy from a plumbing supply house, it is a strong choice; we link Red Lion because it was the brand Amazon itself sold and stocked on the check date. Water Worker also makes 20-gallon tanks; every Water Worker listing we checked was sold by an outside seller. To read the letters on an Amtrol you already own, see our Amtrol well tank model numbers chart.
Before You Buy
- Find your switch setting. It is usually marked under the pressure switch cover: 20/40, 30/50 or 40/60. The pre-charge is 2 psi below the first number.
- Match the connection. The RL20A and RL34A have a 1-inch female elbow connection and the RL44A a 1-1/4-inch one, per Red Lion. The RL6AH has a 3/4-inch male thread. Size the pipe from tank to house to match the pipe from pump to tank, as Red Lion says.
- Check the space. Red Lion lists the carton at 41.7 inches tall for the RL34A. Measure the room, and pick a spot where a leak will not cause damage.
- Look at the water. Red Lion says not to use its tank with water that has sand or clay, and warns that aggressive water can shorten its life. A sediment filter for well water goes after the tank, so it protects your fixtures, not the tank. If the well makes sand, have a well contractor deal with that before you replace the tank.
- Check the pressure limit. Red Lion’s manual does not print a maximum pressure; it says the limit is marked on the tank. It does list pre-charge settings for 20/40, 30/50 and 40/60 switches and calls for a 75 psi relief valve. Check the label when the tank arrives, before you install it. If you need a printed rating before you buy, Amtrol lists 150 psig for its WX tanks.
Installing or Replacing the Tank
Red Lion’s manual tells you to use a licensed electrician or plumber, and to have a qualified professional check the tank and system every year. Turn off power to the pump and open the nearest faucet to drain the tank before you touch anything. Red Lion says to set the pre-charge with the tank empty and no pressure on the system, and never to adjust it on a tank that shows corrosion or damage. If the new tank replaces a steel galvanized tank, remove the old air volume control and remove or plug any bleeder or snifter valves. Install a 75 psi safety relief valve, keep the tank from freezing, which Red Lion says can crack or distort it, and support the tank properly: Red Lion notes that pressure on the connections can cause a failure that the warranty does not cover. Once the tank is running, a gauge such as the ones in our well pressure gauge picks lets you confirm cut-in and cut-out.
FAQ
How big a well pressure tank do I need?
Red Lion’s sizing guide says to take the system’s flow in gallons per minute (one gpm per fixture, which it also uses to size the pump), multiply by 3 and go to the next larger tank. Eight fixtures count as 8 gpm, which gives 24 gallons, so the 34-gallon RL34A. Amtrol sizes by run time instead: one minute for pumps up to 3/4 hp and two minutes for larger pumps, so a bigger pump may call for a bigger tank than Red Lion’s rule gives.
Is a 20-gallon tank 20 gallons of water?
No. Drawdown, the water delivered between pump cycles, is only about a third of the tank’s size. At 30/50, Red Lion lists 7.2 gallons for its 20-gallon RL20A, Amtrol 6.2 for the WX-202, Goulds 6.1 for the V60 and Flexcon 6.8 for the WR 60. Compare drawdown, not gallons.
What should the pre-charge be?
Two psi below the pressure switch cut-in: 28 psi on a 30/50 switch and 38 psi on a 40/60 switch. Red Lion says its tanks ship at 20 psi, so adjust before installing, with the tank empty and no pressure on the system. Amtrol and Goulds tanks ship at 38 psi.
Can I use a bigger tank than the guide says?
Yes, if it fits the space and your pipe connections. Amtrol’s card says a larger tank means fewer pump cycles. Check the connection size first: the RL20A and RL34A use a 1-inch fitting and the RL44A a 1-1/4-inch fitting. Red Lion also says its tanks can be piped in series or in parallel for more capacity.
What warranty do Red Lion well tanks carry?
Red Lion’s manual lists a 5-year limited warranty from the date of original purchase. It also says solids such as sand and clay in the well water can damage the tank and void the warranty, and that a qualified professional should check the tank and system every year.
Why Trust Plumbing Picks
Plumbing Picks is written by a licensed Georgia journeyman plumber. Every size, rating and spec on this page comes from the manufacturer pages and documents listed below, which we opened and read, or from the Amazon listing we link; nothing here comes from hands-on testing. Each linked tank was new, sold and shipped by Amazon, and in stock when we checked on September 28, 2026. Where a link goes to Amazon we may earn a commission at no extra cost to you. Nobody pays to be included here. More on who writes this and how we pick.
Sources
- Red Lion: Pre-charged pressure tanks (product page and specifications)
- Red Lion: Pressure Tank System owner’s manual
- Red Lion: 1-2-3 Easy Guide for Pump and Tank Selection
- Red Lion: product catalog 996508 (pre-charged pressure tanks, carton sizes)
- Amtrol: Well-X-Trol quick sizing card MC7025 (03/26)
- Amtrol: Well-X-Trol installation and operation manual (07/25)
- Goulds Water Technology: Hydro-Pro diaphragm tanks technical brochure (BHYDRO R7)
- Goulds Water Technology: water system tank owner’s manual (IM251)
- Flexcon: Well-Rite series submittal data
- Flexcon: Well-Rite sell sheet (warranty)
- Amazon listings for the Red Lion tanks linked above (read on September 28, 2026)
Bottom Line
Count fixtures at 1 gpm each, multiply by 3 and step up to the next Red Lion size: RL20A for a small system, RL34A for a house like Red Lion’s 8-fixture example. Set the pre-charge 2 psi under cut-in before it goes in, since Red Lion ships at 20 psi. Other makers’ tanks are fine tanks on paper, but on the day we checked they were sold by outside sellers, so we did not link them.