If you are choosing a fiberglass vs steel pressure tank for your well, the right call depends on your water chemistry, where the tank sits, and how long you expect it to last. Cleanflow stocks both Pentair WellMate (composite/fiberglass) and Flexcon Well-Rite (steel). This is a WellMate vs Flexcon comparison from a supplier that carries both lines.
Short answer: Choose WellMate composite if your well water is acidic (pH below 6.5), has high iron, or if the tank goes in a damp or humid space. Choose Flexcon Well-Rite if your water is neutral and the location is dry. On Cleanflow, the composite option is also the more affordable one.
How Fiberglass and Steel Pressure Tanks Differ
What is a composite pressure tank? It is a tank built from layered fiberglass and polypropylene rather than steel. "Composite" and "fiberglass" are interchangeable in this context.
The Flexcon Well-Rite uses a carbon steel shell with Flexcon's patented CAD-2 diaphragm separating air from water. The CAD-2 provides strong air-to-water separation, NSF 61 certification for potable water, and an antimicrobial liner. These steel tanks carry a 5-year warranty.
The Pentair WellMate uses a wound fiberglass shell over a blow-molded polypropylene liner. The inner body is formed as a single piece with no welds or seams, which eliminates weak points where cracks could develop.
There is zero metal anywhere. Instead of a permanent diaphragm, WellMate uses a replaceable air cell (bladder), and the connection fittings are stainless steel or composite. Both types handle 125 PSI and are NSF 61 certified.
WellMate vs Flexcon
|
Feature |
Flexcon Well-Rite (Steel) |
Pentair WellMate (Composite) |
|---|---|---|
|
Shell |
Carbon steel, painted |
Wound fiberglass composite |
|
Interior |
CAD-2 diaphragm (permanent) |
Polypropylene air cell (replaceable) |
|
Corrosion risk |
Vulnerable to acidic and high-iron water |
None. No metal in the tank. |
|
Weight (~20 gal) |
~50-60 lbs |
20.85 lbs (WM-6) |
|
Max PSI |
125 |
125 |
|
NSF 61 |
Yes |
Yes |
|
Bladder service |
Replace entire tank |
Replace only the air cell |
|
~20 gal price (CAD) |
WR-60R: ~$700 |
WM-6: $485 |
|
~40 gal price (CAD) |
WR-140R: ~$1,573 |
WM-12: ~$800 |
This fiberglass vs steel pressure tank comparison is unique to Cleanflow because we sell both brands on the same site. Most guides say composite costs more upfront than steel. On Cleanflow, the opposite is true. The WellMate WM-6 is $215 cheaper than the comparable Flexcon WR-60R, and the gap widens at larger sizes.
Cleanflow carries Flexcon Well-Rite, a high-grade steel line with CAD-2 technology, not budget steel. The comparison is between a corrosion-resistant pressure tank and a top-quality steel one.
Why Tank Material Matters More Than You Think
One detail most guides skip: your pressure tank sits before all treatment equipment. Acid neutralizers, iron filters, and softeners go downstream. The tank receives raw, untreated well water straight from the pump.
If that water is acidic or iron-heavy, the tank material is the only barrier between your well chemistry and corrosion. Everything after the tank is protected by treatment. The tank itself is not.
When to Choose Steel (Flexcon Well-Rite)
A fiberglass vs steel pressure tank debate is mostly academic when your water is clean. If your well pH sits between 6.5 and 8.5, iron levels are low, and the tank lives in a dry, climate-controlled space, Flexcon steel will perform well for 10 to 15 years. The CAD-2 diaphragm is among the strongest available for residential well systems.
If your water is already treated or municipal, you do not need a corrosion-resistant pressure tank. Steel is the proven standard.
When to Choose Composite (Pentair WellMate)
Canadian well water, especially in Manitoba and Ontario, often runs acidic with elevated iron content. If your pH drops below 6.5, a steel tank can fail in as few as 3 to 5 years. A pressure tank for acidic well water needs to be corrosion-proof, and that means composite. WellMate cannot rust, inside or out, because there is no metal to corrode.
Steel tanks also sweat in humid spaces. Cold well water inside the tank causes condensation on the steel surface. That moisture rusts the shell from the outside in, even when the water inside is clean. Fiberglass does not sweat because composite has lower thermal conductivity than steel, so condensation is minimal to nonexistent.
Weight matters for installation. The WM-6 weighs 20.85 lbs, roughly 35% lighter than comparable steel. One person can carry a composite pressure tank in Canada into a crawl space or down narrow basement stairs without help.
Do I need a fiberglass pressure tank? If your water is aggressive, your install space is humid, or you want to avoid full-tank replacement down the road, yes.
The Replaceable Bladder Advantage
When a steel diaphragm fails, the entire tank gets replaced. With WellMate, you swap only the air cell while the shell stays in service. The composite body lasts indefinitely because there is nothing to corrode. Over 20 years on acidic water, you might replace a steel tank 3 to 4 times at ~$700 each, spending $2,100 to $2,800 on tanks alone. One WellMate WM-6 at $485 plus one or two bladder swaps at $50 to $100 each totals under $685 for the same 20 years.
How long does a well pressure tank last? Steel typically runs 10 to 15 years on neutral water and as few as 3 to 5 years on acidic. Composite tanks run 20+ years because the shell does not degrade. The air cell is the wear item, and it is replaceable.
If you are facing a well pressure tank replacement and asking WellMate vs Flexcon, which is better, the answer depends on your water. Both are quality products. The question is whether your water chemistry will shorten a steel tank's life.
Can you replace a steel pressure tank with a composite? Yes. WellMate uses the same standard 1" NPT connection.
Choose the Best Pressure Tank for Your Well
The right fiberglass vs steel pressure tank depends on your water and your environment. Test your pH, check your iron levels, and pick the material that matches.
Cleanflow stocks both Flexcon Well-Rite pressure tanks and WellMate composite pressure tanks, including the WellMate WM-6, and ships across Canada and the USA. Whether you need the best pressure tank for well water with clean chemistry or a pressure tank for acidic well water, both lines are available.
Pair your tank with a 304 stainless steel pressure tank installation kit for a complete setup. The kit includes a 30/50 PSI pressure switch, relief valve, gauge, union, and hose bib. If you also need a pump, read our guide to Flotec shallow well jet pumps for residential water systems.
Browse our complete range of pressure tanks and well pump accessories to find compatible fittings, replacement parts, and other components for your system.
For sizing help, call Cleanflow Utility Supply Company at 1-866-335-1078. Free shipping on orders over $199. Returns accepted within 30 days at returns.cleanflow.net.