pH2 Issues

[peiloy3196]

Hey Guys,
I installed my new apex and everything so far has gone smoothly except for the Ph2 input. After calibration it reads high (8.5 when I am normally between 7.7 - 8.0). I am using it for my tank pH and the pH1 for my calcium reactor.

I took a cup of tank water and put pH2 into it and the readings dropped to about 7.5, which is really low. So i unplugged all my equipment looking for stray voltage while pH2 was submerged in the sump again but it made no difference to my pH reading. I unplugged my ground probe and still no difference. This is driving me nuts:mad2:

Does anyone have and ideas?

[peiloy3196]

Ok so I figured it out....Well sort of. When I unplug my DIY break out box the pH seems to normalize. So I plugged it back in without any floats attached and everything was ok. As I added floats back it interfered with the pH when the float was in a closed state.

I then removed all floats again and using a jumper tested all of the switch input. Every time I closed an input the pH changed.... very strange.

I also noticed that it is both pH inputs that change, but pH2 is much more drastic.

Not sure what to do at this point.

[aquamanic]

Are you running a PM2 module? Is the BB connected to that?

[peiloy3196]

I am running a PM2 Module, but the BB is connected to the main Apex unit. Is that wrong?

[schwaggs]

Nope, not wrong at all. You should be able to connect floats to ANY input. I would contact Neptune support to see what they suggest. My pH does not fluctuate when any of my inputs close on my base or PM2 (I have float inputs on both as well).

[peiloy3196]

I moved the BB to the PM2 Module and the pH seems to be closer to normal. I am guessing something may be wrong with my base module?

[schwaggs]

Not sure about that. I would contact neptune support for that question.

[kenargo]

Ok so I figured it out....Well sort of. When I unplug my DIY break out box the pH seems to normalize. So I plugged it back in without any floats attached and everything was ok. As I added floats back it interfered with the pH when the float was in a closed state.

I then removed all floats again and using a jumper tested all of the switch input. Every time I closed an input the pH changed.... very strange.

I also noticed that it is both pH inputs that change, but pH2 is much more drastic.

Not sure what to do at this point.


It sounds like you have a short in the a float or an incorrectly wired BOB; that can cause all kinds of havoc. Also you may want to turn off Probe Ext (in the setup menu) unless you are using a PX1000.

[peiloy3196]

It sounds like you have a short in the a float or an incorrectly wired BOB; that can cause all kinds of havoc. Also you may want to turn off Probe Ext (in the setup menu) unless you are using a PX1000.

Thanks for the input. I have rewired the BB and still get the same issues. When I move it to the PM2 I do not have the issues anymore. I followed the pinout chart from Neptune when wiring the box with their cable.

How do I turn off Probe Ext and what is it?

[peiloy3196]

So I left off the BOB box and just connected my floats directly to the mini din connector. I plugged the connector into the base unit and and the pH was at 8ish last night when I plugged it in. When I woke up this morning the pH was 4.18. I unplugged the mini din connector and plugged it into the port on the PM2 and the pH has been climbing ever since. At the moment it is at 7.59 and still climbing (an hour after I plugged it into the PM2).

Keep in mind that this is all on the pH2 input. The pH1 input does vary slightly when moving around the mini din connector (around 0.05) but nothing major. I am using the pH1 on my calcium reactor.

Attached is the pH graph.
http://i952.photobucket.com/albums/ae2/Peiloy/pH.jpg