re: pH probes

---------- Forwarded message ----------
Date: Thu, 07 Nov 1996 11:53:03 -0500 (EST)
From: DIONIGI MALADORNO <MALADORD%A1%RNISD0 at mr_nut.roche.com>
Subject: pH probes and CO2 flow
To: AQUATIC PLANTS <Aquatic-Plants at ActWin_com>

Michael Eckardt <mike at odg_com> wrote:
<<<  (...)  Also, I read
somewhere that the life of a probe is 6 months. What are your experiences?

I had a Coralife pH pen that worked fine for about a year, then I let the
probe dry, and it died "beyond remedy"! What upset me was the the
instructions did not clearly recommend to keep it wet, and I learnt only
later that most probes require that. The customer support service of the
manufacturer (actually Coralife is just a distributor) stated that they are
expected to last 1-2 years. During the period of use,  I re-calibrated the
probe twice without finding any difference in readings before and after the
re-calibration (i.e. I was reassured that it was giving consistent results).
I am now using lab. grade color strips.


Subject: CO2 distribution

I have now hooked up the CO2 diffuser of my new 75 gal. to a CO2 tank I use
for the another planted tank. The problem is that the backpressure is
different between the two, and more CO2 goes to the 75gal than to the other.
I have now installed  Netafilm (or something like that) "drippers" for
garden irrigation purposes (rated I think at 2l H2O/hour) on each branch of
the CO2 line, with the hope that they would equalize the backpressure
between the two branches of the system. I had them handy, and they seem to
do the job. They seem also effective as check-valves (can anyone confirm
this?). I did not use two gang valves because I did not have them handy and
I though it might be difficult and time-consuming to find the exact setting
that would equalize the pressure on the two CO2 lines.

I would like to know if anyone has better ways to handle this problem. 


dionigi.maladorno at roche_com