Sequoia Scientific

Returns / Contact Support

Reach Support

If you think you have a problem with your LISST or HydroLight / EcoLight-S product you can contact our support staff via support [at] or via phone +1(425) 641-0944. Note that our business hours are Monday – Friday 9 am – 5 pm Pacific Time.

PLEASE NOTE that for LISST questions we always need the following information:

  • LISST type and serial number (e.g. LISST-Portable|XR sn 785)
  • The raw data files(s) you are concerned about. These have a .DAT or .LOG extension depending on instrument type and model.
  • The zscat file you used for data processing.

For LISST hardware issues, please provide us a detailed description of the issue and what you were doing at the time when you discovered the issue.

RMA Returns

  1. In order to return an instrument to Sequoia for repair or service, please fill out the form below and wait for us to send you an RMA number (0-1 business days).
  2. When you have received the RMA number:
  3. Box the instrument responsibly in original shipping box(es).
    • Include communication cable and power supply.
    • Never take an instrument apart and ship it in pieces.
  4. If shipping from outside the USA:
    • Include Schedule B/ Harmonized code 9801001012 on all shipping documents.
    • Instruct your shipper to use DAP shipping terms, meaning you will pay the total cost of delivery to our door.
    • Include the following description on all shipping documents and your commercial invoice: ‘US GOODS RETURNED’.
    • Specify USA, not your country, as the country of origin (because it was manufactured in the US)
    • Download the Shipper’s declaration, fill it out, and include it with the instrument.
    • Sequoia’s tax ID is # 91-166 87 83 if you need to include that information.
  5. DO NOT USE THE TERM ‘LASER’ ON ANY DOCUMENTATION. Use ‘Particle analyzer’ or ‘Sediment sensor’ instead for descriptive purposes.
  6. Include a complete list of everything in the box.
  7. Write the RMA number on all boxes.
  8. Ship to Sequoia’s address:
    Sequoia Scientific, Inc.
    2700 Richards Road Suite 107
    Bellevue, WA, 98005
    phone: +1-425-641-0944.


Return Authorization Request Form

  • Technical Contact Information

  • Instrument Information

  • Return Shipping Address