600 GPD and a 3:1 pure-to-drain ratio answer different questions
600 GPD and a 3:1 pure-to-drain ratio answer different questions
These two numbers often sit next to each other on an RO spec sheet, which makes them look like one performance score. They are measuring different parts of the job.
| Number | What it describes | What it does not promise |
|---|---|---|
| 600 GPD | Rated production capacity over a 24-hour period | That every kitchen will get the same faucet speed |
| 3:1 pure-to-drain | The stated relationship between product water and drain water under the test basis used for that specification | That four gallons of feed water are needed for three units of product output |
That last point is easy to reverse. A 3:1 pure-to-drain ratio means three units of product water for one unit sent to drain. In a four-unit example, three units reach the faucet and one goes to the drain.
The unit conversion is useful too:
600 gal/day × 128 oz/gal ÷ 1,440 min/day ≈ 53.3 oz/min
That is the math behind the daily rating. It is not a stopwatch result for your sink. Feed-water pressure and temperature, incoming water quality, filter condition, and the way water is drawn can all affect what happens at home.
Why there's wastewater at all: RO works by pushing feed water through a membrane. Only a portion becomes product water, while the rest becomes reject stream (concentrate) carrying the contaminants that were removed, so it must be sent to drain. So wastewater is a normal byproduct of this separation process, not necessarily system-specific waste.
For the Vortex 6 Pro, the current US product information lists 600 GPD and a 3:1 pure-to-drain ratio. The public numbers are useful for comparing specifications, but the public product page by itself does not provide enough detail to turn either one into a guarantee for a particular cabinet and water supply.
If you want to check your own setup, keep the questions separate:
- Speed: How long does it take to fill a container of known volume?
- Drain volume: Over the same stable interval, how much product water and drain water are collected?
Which matters more in your kitchen right now: waiting at the faucet, or the amount of water going to drain?
Posted Aug 8, 2026, 5:37 PM UTC