pH out of whack

[fickle1]

I think I finally have all of the bugs worked out with my coding, but something is messed up with my pH. It will be stable for hours then all of a sudden get a huge spike.

I checked the other outlets at these times and nothing seems to match up like it would be causing interference. The pH probe is about 3 weeks old. It calibrated fine and when I put it back in the calibration fluid afterward, it was right on. What else could cause these spikes?

 

[kurt_n]

Where is the probe located in your system, and what is it next to?

 

[fickle1]

Where is the probe located in your system, and what is it next to?

The probe is located in the sump. It is mounted in this probe holder beside the temperature probe.

http://www.poorboyaquatics.com/products/magnetic-probe-holder/magnetic-probe-holder.html

The only other thing currently in the sump is the Tunze return pump and the heater. I thought the issue might be the heater since it was a stealth pro. I replaced it with a Aqueon pro heater and the issue is still there.

 

[aquamanic]

That graph looks like really bad interference. If you put the probe is a cup of tank water, do you get those bizzare readings? Is there anything on the bottom glass ball of the probe?

 

[fickle1]

That graph looks like really bad interference. If you put the probe is a cup of tank water, do you get those bizzare readings? Is there anything on the bottom glass ball of the probe?

I haven't tried putting the probe in a cup of water yet. I will have to try that later. What would I be looking for on the probe? Like algae or something? The tank is only 2 months old and I am still letting it cycle, so there is nothing in the tank yet.

looking back through my graphs I found the one from when I first set it up.

It was maxed out until I unplugged the probe and plugged it back it. This has happened a few times since then and unplugging it and plugging it back in seems to resolve the issue for a while. I still get those spikes every few hours though.

 

[kurt_n]

Do you get a spike at all if you wiggle the connector at the base unit? Agree that it looks like some type of interference, or intermittent connection.

 

[aquamanic]

I think you have to try and eliminate the most obvious first and that would be interference - electrical or physical. Inspect the probe for anything at all on the glass bulb. Probably not but worth a look.

Then remove the probe from the Apex, pull all the wire out so it's not near your tank at all. Plug it back in and put the probe in a cup of tank water. Monitor and see if probe still spikes.

If it does, then I'd suspect a faulty probe.

If it behaves correctly, then you have to gradually put it back into service. First just put the probe in the tank with the wire still outside the tank on the floor. If it flakes then there's something in your tank/sump. If not, then reroute the wire and see what happens.

Big process of elimination.

 

[fickle1]

I think you have to try and eliminate the most obvious first and that would be interference - electrical or physical. Inspect the probe for anything at all on the glass bulb. Probably not but worth a look.

Then remove the probe from the Apex, pull all the wire out so it's not near your tank at all. Plug it back in and put the probe in a cup of tank water. Monitor and see if probe still spikes.

If it does, then I'd suspect a faulty probe.

If it behaves correctly, then you have to gradually put it back into service. First just put the probe in the tank with the wire still outside the tank on the floor. If it flakes then there's something in your tank/sump. If not, then reroute the wire and see what happens.

Big process of elimination.

I pulled out the probe and everything looked fine with the probe itself. I ran the cable around the front of the tank away from everything and put it in a cup of tank water. About an hour later I started getting the same spikes. It is a BRS pH probe. I know that they test them before shipping them. Is it still possible that it is a bad probe?

 

[aquamanic]

That would be my suspect. If they'll swap it, you'll know for sure. I suppose it's possible it's the base module but that would be such a remote possibility that I wouldn't even consider it at this point.