RO TDS Limit – How Much TDS Is Too Much for Your RO System?

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Understanding the relationship between TDS levels and the performance of a reverse osmosis system is important if you want to get the most out of your filtration setup.

Reverse osmosis generally has a very good TDS rejection rate, but any system also has its limitations – sometimes feed water TDS levels are simply too high to handle.

Let’s take a look at some examples and discuss how you can determine the TDS limit of your RO system.

Key Takeaways

  • Different reverse osmosis systems have different TDS limits. Anything between 500 and 2,000 ppm is possible.

RO TDS Limit – How Much TDS Is Too Much for Your RO System?

So, what’s the RO TDS limit of your filtration setup?

Well, it depends mainly on the components used in your RO system. Some units are capable of supporting higher TDS levels, sometimes up to 2,000 ppm, like the Ultimate Series by APEC. The AquaTru countertop reverse osmosis system can handle up to 1,500 ppm.

In other cases, the limit is much lower. For example, if you’re using the SimPure Y7P-BW, your feed water TDS levels should not exceed 500 ppm. Likewise, if you’ve got an iSpring model, it’s advisable to keep the TDS level below 750 ppm.

This doesn’t mean that you always need to go for the model with the highest supported TDS levels though. It’s rare that you’d find TDS levels in your water supply that are such high, and in most cases, something more around the middle is going to work just fine.

Still, you want to consider measuring the TDS levels of your feedwater before investing in a reverse osmosis system to ensure that you’re getting the best model available for your needs.

RO TDS Limit – Real Life Examples

Here are some real life examples of RO TDS limits:

Reverse Osmosis System Max TDS Levels
AquaTru Countertop RO System 1,500 ppm
APEC Ultimate Series Reverse Osmosis Systems 2,000 ppm
iSpring Reverse Osmosis Water Filtration Systems 750 ppm
Pentair PRO-RO 6-Stage Reverse Osmosis System 2,000 ppm
Aquasana OptimH2O Reverse Osmosis System 1,000 ppm
Home Master Reverse Osmosis Systems 1,500 ppm
SimPure Y7P-BW Countertop RO System 500 ppm

What Are TDS Levels in Water?

TDS stands for Total Dissolved Solids, and it measures exactly what the name implies – the concentration of dissolved solids in your water. Note that this is not a general measurement for contamination, as many contaminants will not be caught by these measurements, while many healthy impurities will.

How Do You Measure TDS?

tds meter in glass of water

Measuring the TDS levels of your water can be easily done with a portable TDS meter. You just need to take a sample of water, swirl it around a little bit to ensure there are no bubbles, and submerge the TDS meter up to the indicated level to get a reading.

Ideal TDS Levels in Drinking Water

If you want your drinking water to be as pure as possible, you should aim to bring its TDS down to below 300 ppm. Reverse osmosis systems do a great job at this, as they can easily reduce TDS levels to as little as 10-50 ppm. Between 300 ppm and 600 ppm is still acceptable, though it starts to border on unpleasant levels.

If you have any questions about RO TDS limit please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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