Help.

I have an Ultralife Reef Products pH Monitor and Controller Model
MC-101. I am attempting to convert to the use of this with a Pinpoint
pH probe to turn my CO2 on and off. I had been using the pH monitor
and probe on another tank just to monitor the pH and had been simply
been turning the CO2 on and off with the tank lights via standard
timers and a solenoid.

The problem I have is when the controller attempts to turn the CO2 off
(I suspect on, but the effect is not as bad). When the pH drops to
the point that the CO2 should shut off, the controller "clicks" but
then the reading climbs a few whole points then starts to settle back
down. Once it reaches the cut off point again, the cycle repeats.
So, approaching 6.90 when the trigger to turn off the gas occurs,
controller clicks and then the reading jumps to 8.5 and starts to come
down.....gets back to 6.9 and then repeats. The controller clicks,
but the solenoid never fires.

At first I thought this was a ground issue. I put in a new ground rod
and grounded the tank. No change. I then put the pH probe into a
small container of tank water beside the tank. Same events.

I also note that the pH reading swings when I turn on or off the tank
lights.

So, have I got a bad pH monitor, bad probe or something else? I am
stumped. I suspect the controller is bad and is unable to fire the
solenoid and exibits the bad effects in the ramped up readings.

On Fri, 25 Apr 2003 20:36:24 -0400, James Ervin
wrote:

Help.

snip

So, have I got a bad pH monitor, bad probe or something else? I am
stumped. I suspect the controller is bad and is unable to fire the
solenoid and exibits the bad effects in the ramped up readings.

Hi,

One issue that you may investigate is if you are running electronic
ballasts, you MUST keep the pH sensor wiring (and anything else
electronic) away from them, the tubes and the wiring. The high
frequencies they operate will radiate into surrounding wiring and
effect the accuracy of the units.

I have witnessed this effect on both pH and temperature sensors and
their associated wiring in close proximity to switching ballasts.

One other factor to consider is whether the power supply of the pH
controller has enough (milli)amperage to handle the current draw of
the solenoid.

Greg

New information:

If I plug a simple appliance (say a hand held blower) into the
controller, it cycles on and off as expected. If I remove the outer
part of the CO2 solenoid, (I think this part is just a big electro
magnet, but am not sure) and hook this up to the controller, the unit
simply cycles as described. How can I test the load that the solenoid
is putting on the controller?

I will try and simulate a high load on the controller and see if I can
reproduce the effect.

On Fri, 25 Apr 2003 20:36:24 -0400, James Ervin
wrote:

Help.

I have an Ultralife Reef Products pH Monitor and Controller Model
MC-101. I am attempting to convert to the use of this with a Pinpoint
pH probe to turn my CO2 on and off. I had been using the pH monitor
and probe on another tank just to monitor the pH and had been simply
been turning the CO2 on and off with the tank lights via standard
timers and a solenoid.

On Sat, 26 Apr 2003 03:27:06 -0400, Greg One issue that you may
investigate is if you are running electronic
ballasts, you MUST keep the pH sensor wiring (and anything else
electronic) away from them, the tubes and the wiring. The high
frequencies they operate will radiate into surrounding wiring and
effect the accuracy of the units.

This explains why the temp probe and the pH probe fluctuate when the
lights go on or off........they are about 18" from the ballast that is
mounted in the hood (Ice Cap 660 Yea baby).

I will move the probes deeper into the tank.

The other cycling that happens when the controller attempts to turn
the CO2 off happens when the lights are off as well, so I appear to
have too issues. Wow. I should go back to just turning the CO2 on
with the lights or leaving it on all the time.

I like the idea of using the probe, as you can target the CO2 ppm that
you want based on your kH.

This tank also has an under gravel heater so there is a lot of juice
floating around.