RO design software compared: six vendor tools and a cross-brand alternative

1. Why six programs exist

Membrane manufacturers build design software for a clear reason: they want their membranes calculated with the mass-transfer model they consider correct, so a customer does not compute a deviation with someone else's model and then question the product. Every program is therefore centred on that vendor's own model and its calibrated parameter set.

That creates a practical problem for design institutes and EPC contractors. To compare three brands on one project you build the model three times, re-enter the water analysis, the array and the recovery, and then align the outputs by hand. If the assumptions differ, the comparison can even invert.

2. Capability comparison

Licensing, versions and features change; the table above is an engineering summary and the vendor's own documentation prevails.

3. Where each one stops

Still looking for ROSA?

ROSA (Reverse Osmosis System Analysis) was Dow's earlier RO design program. As Dow's water business moved into DuPont, its functions were taken over by WAVE. The ROSA 9.0 installers circulating online are years old and their membrane database stops at the product line of that time, so recent models are missing. If you only need to re-check an old project, compare against the original calculation report rather than re-running old software.

Where vendor software is strong

Parameters are maintained by the manufacturer and the model is calibrated against that vendor's own membrane tests, which is generally easier for all parties to accept in tendering, warranty and dispute situations. Where a warranty commitment is involved, the final report is usually required to come from the official program.

Where vendor software stops

• It cannot cross brands. You cannot calculate a DuPont element in Hydranautics software; substituting an approximation leaves an uncontrolled error.
• Installation and licensing cost. Desktop programs are usually tied to Windows and require an account, which is awkward for remote collaboration and quick checks.
• Fixed report format. Converting output into a company template usually still means manual work.

4. Comparing several brands in practice

The workable process has two stages:

1. Compare with a cross-brand tool at the option stage. Same water analysis, same recovery, same array, run three brands once each; look at which has the better flux distribution, pressure and concentrate saturation, and converge on one or two options quickly.
2. Verify with the vendor's official program before delivery. Confirm that the final selection's parameters and warranty basis match, and issue the official report.

This keeps comparison speed without giving up compliance. The key is that assumptions must match between the two stages — if membrane parameters in the cross-brand tool differ substantially from the official program, the two conclusions are not comparable.

5. Migrating existing projects

Re-entering a project takes longer than people expect: a dozen ions, the array, vessel counts, recovery, temperature, pump data. The practical route is to parse the project files the official programs already save:

• Hydranautics: .desx (new) and .des (legacy)
• Toray: .tds2
• LG: .qplus
• Vontron: .von
• Veolia: Winflows project format is not public, so import is not supported

After import you still have to verify by hand: whether the model exists in the library, whether the array was reconstructed correctly, and whether units match (bar/psi, m³/h/gpm). Import removes typing, not judgement.

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