[Nhcoll-l] Deionized water systems and standards

[Alexandra Snyder]

We mix our museum's ethanol and formalin preservative chemicals using deionized and reverse osmosis water, which is delivered via a recirculating system (5 gpm) to about 75 points of use, building wide.  The current cost for maintenance is about $7,000 annually, which takes a big bite out of our operating budget for the museum.  In setting up the system about 12 years ago, I asked for deionized water, only, because we do not need ultrapure/double distilled water.  I questioned whether we needed RO system and UV system with filter (installed as well) because the water is recirculating and biological contamination should not be a factor in water quality.  Of course the biggest cost in the maintenance is exchanging the mixed resin bed filters, every three months.  Our use is low, about 2500-7000 gallons per year, so I am wondering if this is excessive.

In order to consider options for getting DI water that is sufficiently pure for general lab use and mixing chemicals (i.e., most of the mineral content and dissolved ion content removed) and not "high end" pure water needed in semiconductor labs, I  am seeking information from the listserv re: what minimal standards (conductivity and resistivity) should be met for DI water used in mixing specimen preservation chemicals.  Also, if we have to abandon a building wide system for now, I would like to hear from anyone who may have experience with the single point of use portable systems (e.g. Silex Deionizers) for lab use.

Thank you for your attention to this question.

*************************************
Alexandra M Snyder, Collections Manager-Fishes
Museum of Southwestern Biology MSC03-2020
University of New Mexico Albuquerque NM 87131
PH./FAX 505.277.6005     amsnyder at unm.edu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20130514/3f3b1241/attachment.html