As a trusted source for water filtration solutions, one question we frequently get at Isopure Water is: How often should a reverse osmosis (RO) storage tank be replaced? It’s a smart question—after all, the tank plays a key role in your system’s performance, and over time, its efficiency can degrade without warning.

Let’s break it down together so you’ll know when—and why—to replace your RO storage tank to keep your drinking water system running at peak performance.

Understanding the Role of an RO Storage Tank

A reverse osmosis storage tank is the part of your system that holds purified water after it has passed through the filtration stages. It allows you to get filtered water on demand without having to wait for it to be processed in real-time.

These tanks contain two chambers:
  • An air bladder that maintains pressure
  • A water chamber lined with a rubber bladder that expands as it fills
When you open your faucet, the compressed air pushes the water out without needing an electric pump. If the air bladder leaks or the internal bladder fails, your tank won’t work correctly—and you’ll likely experience slow flow, low pressure, or a constant stream of water from your drain line.

How Long Does an RO Storage Tank Last?

On average, a quality RO storage tank will last 5 to 10 years. However, several factors influence the actual lifespan:


1. Water Quality

Hard water or high levels of chlorine can degrade internal components faster. Sediment can also accumulate inside over time, stressing the bladder and valves.


2. Usage Frequency

Households with high daily water consumption may put more cycles on the tank, leading to faster wear.

3. Air Pressure Maintenance

Your tank’s internal air pressure (typically 7-8 PSI when empty) should be checked periodically. Incorrect pressure can shorten its lifespan.


4. Build Quality

At Isopure Water, we only carry high-performance tanks made with NSF-certified materials and FDA-approved bladders. For example, our PAE RO-132 4.0 Gallon Storage Tank is a best-seller for a reason—it’s built for long-term durability and wide system compatibility.

Signs Your RO Storage Tank Needs Replacement

So how do you know when your RO storage tank should be replaced? Look for these symptoms:
  • Reduced water flow even when filters are new
  • Low water pressure from the RO faucet
  • No water dispensing at all
  • Constant drain line running (indicating the system isn't shutting off)
  • Unusual taste or odor due to stagnant water
  • Visible leaks or corrosion on the tank exterior
If you’ve verified that your filters and membrane are in good condition and you’re still experiencing these issues, chances are high the tank has failed.

Can You Replace Just the Bladder Inside the Tank?

In most cases, no. RO storage tanks are sealed units, and the internal bladder isn’t serviceable. Once it fails, the entire tank must be replaced.

How to Extend the Life of Your RO Storage Tank

While they’re not meant to last forever, you can help your tank last longer by:
  • Checking air pressure annually (use a digital tire gauge at the air valve)
  • Sanitizing your RO system once a year to prevent bacterial growth
  • Using pre-filters to trap sediment and chlorine before reaching the tank
  • Installing your tank indoors or away from direct sunlight to prevent heat stress

Shop Reliable RO Storage Tanks from Isopure Water

If your tank is showing signs of wear or simply overdue for replacement, we’ve got you covered. At Isopure Water, we stock a curated selection of high-quality tanks for both residential and commercial RO systems.

Here are a few great options:
Order online today and get fast shipping direct to your door. And if you’re not sure which tank fits your system, give us a call at (714) 541-6600—we’re here to help.