The HI-98129 is the one I use almost daily at work. It is great, and very
accurate so long as you follow the instructions precisely, and are careful
with it. These sort of meters are sensitive instruments--treat them with
the care they deserve and you will be assured of accuracy AND longevity.
(My current 98129 is nearly two years old and works like new.) I find
that
the majority of fish folks are quite negative about pH meters, and that
for
the most part their comments indicate that they dont really understand how
to treat the instrument.


I never remember the make of mine will look tonight, (I think it's German
and available in most French fish stockist)

Mine is fantastic, measures and controls my pH via a CO2 solenoid valve,
measures to the hundredth, and have never had a problem with it, makes
keeping discus, and good plants so much easier. Can't praise it enough.
Needs to be calibrated every month or so, but compared to cleaning the tank,
is hardly a burden.

Cheers

A