I had several inquiries about the water system we have for a molecular
biology facility that does cell cultures, DNA/RNA, RT-PCR, monoclonal
antibody production, histopathology and EM included.

The system is Millipore

1.  it pulls water from city water supply
2.  into a Millipore-RO 12 plus system, goes to storage tanks made by
Millipore,
3.  This water is then pulled into a MilliQ plus system for ultrapure water
    that all the labs use for their superclean technics.

It holds a pH of 6.68 or so, consistently.

Hope this helps. All these labs have few problems with water
since we switch to this newer water system.  People still have to clean
their individual lab storage containers regularly to avoid growth of strange
floating critters!

Gayle Callis