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View Full Version : Apex Conductivity probe not stable!


BlackTip
08/11/2015, 07:47 AM
I installed the Apex conductivity probe 3 weeks ago. I installed it and calibrated it per instructions. The initial reading was off by 1 full point, but the reading was somewhat stable. The reading was between 31.5 - 32.1. My Milwaukee refractometer reads 32.

In the past two days, the reading fluctuate too much. It goes to 32.5, then withing ours drops to 29. I relocated the probe from between the baffle to the return section. Again, it went up to 32+ then drops to 29. It keeps doing this.

Is this probe faulty?

I have my outlets programmed to when the reading goes below 31. Yesterday, I had warning, alarm, text and email going off. I had to go home in the middle of work day to make sure everything is OK, and I woke up in the middle of the night on the alarm sound. I took the programming code out for now.

slief
08/11/2015, 12:29 PM
You either don't have it calibrated properly or didn't let it settle in long enough before calibrating. FWIW, they should be in the water for about a week and then recalibrated for best accuracy. Also, when you calibrate, you should have the temp probe associated with the conductivity probe in the calibration solution so that temperature compensation is accurate. You also need to allow the probe plenty of time to settle during the calibration process and swirl the probe in the solution so that there are no air bubbles trapped in the probe tip.

You may have it in a heavily aerated area of your sump which can cause the Conductivity to be lower than expected.

Your Conductivity could actually be about 29. Have you measured your salinity with a properly calibrated refractometer?

Lastly, what is the salinity of your water when measured with a calibrated refractometer? FWIW, you should always calibrate your refractometers with 1.026 calibration solution and not distilled water.

Lastly, if you have stray voltage in your tank and or have the probes wires running parallel to any power cables, that can cause interference with the probe and instability in the readings.

All said, if I had to guess, you didn't allow the probe to settle in long enough in the tanks water before you calibrated it and likely need to recalibrate the probe. That or your salinity in your tank is lower than you think.

BlackTip
08/11/2015, 01:00 PM
I calibrated the probe per instructions. It is connected to PM2 and the Temp probe is also connected to the PM2. It is configured to read salinity. That was 3 weeks ago. I didn't re-calibrate, because I don't have extra solution as of now.

My brand new and calibrated Milwaukee refractometer reads 32 each time.

All of my probes were located between the baffle, and they were fine. After the fluctuation of the Conductivity probe, I moved all of the probes to the return section. Water is very clam and stable there.

I thought of stray voltage, but I didn't add any addition equipment since then. The heaters are not even on.

Here is the chart for the today:

http://reefcentral.com/forums/picture.php?albumid=9917&pictureid=71083

Jyetman
08/11/2015, 01:16 PM
Don't forget to tilt the probe at a 45 degree angle. This helped fix mine.

karimwassef
08/11/2015, 01:21 PM
I have one so I sympathize.

These probes are very sensitive to bubbles and particles. You need to find a quiet place where particles and bubbles are non-existent.

Make sure it's clean and 100% dry during the dry-cal portion. Make sure there are no bubbles during the wet-cal.

Finally, mine was susceptible to electrical interference. Look at the wires next to the probe wire. Do you have a powerhead wire? Heater wire?

You'll need to play around to reduce the noise.

In my case, I basically accept the variation as long as it's generally between two known states. I use it to look for big things, not fine measurement.

slief
08/11/2015, 03:12 PM
I calibrated the probe per instructions. It is connected to PM2 and the Temp probe is also connected to the PM2. It is configured to read salinity. That was 3 weeks ago. I didn't re-calibrate, because I don't have extra solution as of now.

My brand new and calibrated Milwaukee refractometer reads 32 each time.

All of my probes were located between the baffle, and they were fine. After the fluctuation of the Conductivity probe, I moved all of the probes to the return section. Water is very clam and stable there.

I thought of stray voltage, but I didn't add any addition equipment since then. The heaters are not even on.

Here is the chart for the today:

http://reefcentral.com/forums/picture.php?albumid=9917&pictureid=71083

To me it looks like your temp compensation is off or you didn't calibrate salinity with the temp probe in the solution or the calibration solution was different than the tank temp. I assume you have a second temp probe connected to the PM2? If not, did you assign the primary temp probe to the CondX probe for temperature compensation?

Can you post a graph for both temp and CondX? There is likely some correlation between that and Conductivity. The swing from 29 to 32 is a big swing. I'd expect to see swings of around .2 to maybe .4 which isn't enough to show up on a refractometer but 29-32 is a pretty big swing. That leads me to believe it's temperature related or something else in the tank that turns on and off at certain intervals like a DC pump, power head etc that could be producing stray voltage.

BlackTip
08/11/2015, 04:02 PM
I have only one temp probe. It is assigned to the conductivity probe. The temp compensation is 2.2. When I calibrated, I didn't have the temp probe in the solution, but I had the solution bag in the same water.

My temp probe started to act up as will. Temp started climbing for no reason. I tested with 3 other thermometers and the reading were: 80F, 80F, 79F, but the probe reads 80.8

http://www.reefcentral.com/forums/picture.php?albumid=9917&pictureid=71098

slief
08/11/2015, 06:06 PM
Have you updated the firmware on your PM2? You might want to do that and then recalibrate. You don't have a temp probe on your base unit? Only on the PM2? If so, you should be able to move the temp probe to the base unit and select that temp probe as the one for the PM2. I'm asking that because TempX5 is the same name my PM2 temp probe uses where as my base temp probe is called "temp"

BlackTip
08/11/2015, 06:41 PM
Have you updated the firmware on your PM2? You might want to do that and then recalibrate. You don't have a temp probe on your base unit? Only on the PM2? If so, you should be able to move the temp probe to the base unit and select that temp probe as the one for the PM2. I'm asking that because TempX5 is the same name my PM2 temp probe uses where as my base temp probe is called "temp"

When I was installing them, in the BRS video and the intruction manual, they strongly advice to have the Temp probe plugged into the PM2. They said, it will be more accurate this way.

I am going to order calibration solution and do it over.

BTW, what is the best place in the sump to place the probes?

slief
08/11/2015, 07:28 PM
When I was installing them, in the BRS video and the intruction manual, they strongly advice to have the Temp probe plugged into the PM2. They said, it will be more accurate this way.

I am going to order calibration solution and do it over.

BTW, what is the best place in the sump to place the probes?

A place of high flow with minimal light and ideally, no micro bubbles. That said, the drops in your graphs make me suspicious (29-32 Salinity). That's equivalent of going from 1.021 to 1.0236. Something isn't right and there also seems to be a pattern to the salinity drops and peaks in your graphs. That said, from 14:00 on, it seems to have flatlined at 32 (salinity).

Not sure about the validity to what BRS mentioned in their video. I run separate temp probes and as part of my redundancy.

jason2459
08/11/2015, 07:44 PM
Yes you can't use the temp prob for the conductivity from any other input. It has to be in the pm2 to work with the conductivity probe.

You need to have the temp probe in the same solution during calibration. You have to make sure they are well rinsed and completely dry before calibration.

Make sure the temp probe is next to the conductivity probe in the sump/tank. You can adjust the compensation up or down as needed.

Your return pump could be the main issue. There's a lot that can interfere with a conductivity probe or any probe for that mater.

jason2459
08/11/2015, 09:28 PM
Also I would suggest the Neptune 53mS solution. Not another brand. Yes, they are different. No, you will not be able to calibrate a refractometer with it as it is does not have a salinity of 35ppt.

BlackTip
08/12/2015, 07:38 AM
I filed a ticket with Apex, and they responded by saying that I need to re-calibrate and move the temp probe from the PM2 to the main module with 0.0 compensation.

The manual, however, states the following:

" In order for the PM2 to automatically compensate for changes in conductivity as the temperature
of the water changes, you must connect a temperature probe to the PM2 and set the temperature
compensation as described below. The temperature probe connected to the Apex Base Module cannot be
used for automatic temperature compensation on the PM2."

jason2459
08/12/2015, 07:42 AM
I filed a ticket with Apex, and they responded by saying that I need to re-calibrate and move the temp probe from the PM2 to the main module with 0.0 compensation.

The manual, however, states the following:

" In order for the PM2 to automatically compensate for changes in conductivity as the temperature
of the water changes, you must connect a temperature probe to the PM2 and set the temperature
compensation as described below. The temperature probe connected to the Apex Base Module cannot be
used for automatic temperature compensation on the PM2."

Would be interested in clarification on their suggestion. My understanding as well is that would not allow for any ATC with the conductivity probe.

BlackTip
08/12/2015, 07:54 AM
Would be interested in clarification on their suggestion. My understanding as well is that would not allow for any ATC with the conductivity probe.

I responded to their email, and asked for clarification already.

BlackTip
08/12/2015, 07:57 AM
Have you updated the firmware on your PM2? You might want to do that and then recalibrate. You don't have a temp probe on your base unit? Only on the PM2? If so, you should be able to move the temp probe to the base unit and select that temp probe as the one for the PM2. I'm asking that because TempX5 is the same name my PM2 temp probe uses where as my base temp probe is called "temp"

I have only one temp probe. I updated the firmware 3 weeks ago.

The funny thing is that everything was working fine for 2 weeks, before it went crazy.

The Conductivity probe reading has been stable since yesterday.

jason2459
08/12/2015, 08:10 AM
I have only one temp probe. I updated the firmware 3 weeks ago.

The funny thing is that everything was working fine for 2 weeks, before it went crazy.

The Conductivity probe reading has been stable since yesterday.

Nice. Could be many things that will cause it to swing around. Also, having it in your return section or the baffles just before it could also be thrown off by anything at all you might be dosing or like stated above any kind of microbubbles produced by various things like the skimmer, drains, turbulence going over/through the baffles, etc.

I've always had my probes in the least turbulent area, with as little light as possible or none at all hitting them, and upstream from any kind of dosing. Even ATO of fresh water will through it off. Lime water top off even worse.

I would still get another temp probe in another section just as a check and balance like slief said above as well. I've some how gone way overkill on temp probes and probes in general.

Behind my display tank I have an external overflow for my beananimal. No light directly hitting it and in the corner of it there's very little turbulence. I have there a temp probe, pH probe, and ORP probe.

In the drain section of my sump in the opposite corner of where the drains are is low turbulence, upstream from any dosing (I do vinegar and kalk top off), and I do not have it lit. I have there a ranco temp probe and then the apex temp, conductivity, and another pH probe. I also have a temp thermometer stuck on the inside I can read through the glass. I also have my old reefkeeper temp/pH/conductivity probes still in there as I just switched over to the apex.

I cross check all those. They are all with in hundredths or tenths of degrees of each other and so far fairly stable minus when I screw with them.

BlackTip
08/12/2015, 08:17 AM
I may have to design something. There is no place in the sump that meet all of the criteria (no micro bubbles, low flow, low light). I have 5 sections in my sump - drain, skimmer, gfo/carb reactor, return, and fuge. The calmest section is the fuge, but it is let at night. The second suitable section is the return section. That were the probes located right now. Previously, they were located in between the baffles right before the return section. There is high flow area.

jason2459
08/12/2015, 08:36 AM
I'd put it in the drain section in a corner away from equipment and drain if possible. You could also create pvc probe well(s) for them. Google search aquarium pvc probe well. Lots of DIY mods out there.

jason2459
08/12/2015, 08:40 AM
Also, to clarify when I mentioned my readings have been stable is that they vary in a dependable and expected pattern with in a target range. If my readings don't change through out the day I think something is wrong.

BlackTip
08/12/2015, 08:41 AM
I'd put it in the drain section in a corner away from equipment and drain if possible. You could also create pvc probe well(s) for them. Google search aquarium pvc probe well. Lots of DIY mods out there.

Yes, I was thinking about a box or a well. But I can't put them in the drain section. The main reason is the controller and the drain section is on opposite side of the stand (8' apart). I will need a lot of extensions. Also, I have micro bubbles there, and the plan was to put a bio-pellet reactor in that section when/if needed.

I think my best bet is the return section and a well or a box of some sort.

jason2459
08/12/2015, 08:46 AM
I would avoid the return section. That area to me is a no go zone particularly for temp probes as it could drain.

slief
08/12/2015, 09:54 AM
I filed a ticket with Apex, and they responded by saying that I need to re-calibrate and move the temp probe from the PM2 to the main module with 0.0 compensation.

The manual, however, states the following:

" In order for the PM2 to automatically compensate for changes in conductivity as the temperature
of the water changes, you must connect a temperature probe to the PM2 and set the temperature
compensation as described below. The temperature probe connected to the Apex Base Module cannot be
used for automatic temperature compensation on the PM2."

My understanding is that you no longer need the temp probe connected to the PM2. Neptune made a firmware change a few months back that allows you to associate the base units temp probe to the conductivity probe so that you aren't dependant on having a temp probe connected to the PM2. This is why I mentioned associating the probe in my previous post. That would be the first thing I would try as well as finding a place in your sump without direct light and little to no microbubbles. You don't want algae growing on your probe and you also don't want air getting trapped in the probe and skewing the readings. What I don't know is how you associate the temp probe on the base unit to the CondX probe. I think that may have to be done through the display.

jason2459
08/12/2015, 09:59 AM
I just went through calibration a couple times now (from the display unit) and on the latest firmware and module updates. I don't recall seeing where you can associate the conductivity probe with any other temp probe. I would be interested if this is there because I don't want it associated with the base unit's temp probe that is up with the display while the conductivity probe is 15' away in the sump where the temp is higher.

BlackTip
08/12/2015, 10:02 AM
My understanding is that you no longer need the temp probe connected to the PM2. Neptune made a firmware change a few months back that allows you to associate the base units temp probe to the conductivity probe so that you aren't dependant on having a temp probe connected to the PM2. This is why I mentioned associating the probe in my previous post. That would be the first thing I would try as well as finding a place in your sump without direct light and little to no microbubbles. You don't want algae growing on your probe and you also don't want air getting trapped in the probe and skewing the readings. What I don't know is how you associate the temp probe on the base unit to the CondX probe. I think that may have to be done through the display.

Well, that make sense. I wish they'd have updated the instruction manual.

slief
08/12/2015, 10:45 AM
Well, that make sense. I wish they'd have updated the instruction manual.

The comprehensive instruction manual was written by a long time dedicated Apex user and was originally intended as the unofficial manual for all things Apex. It was written without any input or support from Neptune systems as a tool for users since Neptune didn't have very good documentation on advanced features and programming. As of about a year ago, Neptune include this great document on their support site. I'm not sure why he hasn't updated it in a while though.

BlackTip
08/12/2015, 10:59 AM
The comprehensive instruction manual was written by a long time dedicated Apex user and was originally intended as the unofficial manual for all things Apex. It was written without any input or support from Neptune systems as a tool for users since Neptune didn't have very good documentation on advanced features and programming. As of about a year ago, Neptune include this great document on their support site. I'm not sure why he hasn't updated it in a while though.

That is shocking to hear. They sell their products for hundreds of dollars and can't even bother of providing a simple instruction manuals?

The manual I was referring to is the PM2 manual on their website.

https://www.neptunesystems.com/downloads/docs/PM2_manual.pdf

slief
08/12/2015, 11:19 AM
That is shocking to hear. They sell their products for hundreds of dollars and can't even bother of providing a simple instruction manuals?

The manual I was referring to is the PM2 manual on their website.

https://www.neptunesystems.com/downloads/docs/PM2_manual.pdf

That isn't the manual I was referring to. It was the Comprehensive Apex Manual.
https://www.neptunesystems.com/downloads/docs/Comprehensive_Reference_Manual.pdf


That said, Neptune has been hard at work designing new products and making manuals and updating them can be a pretty big task so I am not suprised they are a bit behind. On that note, the official Neptune Forum is a great resource for all things Apex and these kinds of updates are always discussed there along with new features. It's also a great place to ask a question if you have one because the official forum is monitored by Neptune Systems as well as countless Apex experts.

https://forum.neptunesystems.com/

Jyetman
08/12/2015, 11:59 AM
If a TEMP probe is connected to the PM2 does that probe become default?

karimwassef
08/12/2015, 12:09 PM
No. You need to set it in the views and formulae.

jason2459
08/12/2015, 12:24 PM
No. You need to set it in the views and formulae.

Where would that be?

karimwassef
08/12/2015, 12:31 PM
There is no 'default'. The Temp is just the variable that's shown in the front panel and shows up in each of the module programs.

My PM2 temp probe shows up as Tmpx6 and I go on Fusion on a computer and change all the Temp to Tmpx6. I pull down the dashboard for Temp and put the Tmpx6 in its place, etc..

For the display, I went back to the classic (local IP) site and change the display settings.

jason2459
08/12/2015, 12:38 PM
There is no 'default'. The Temp is just the variable that's shown in the front panel and shows up in each of the module programs.

My PM2 temp probe shows up as Tmpx6 and I go on Fusion on a computer and change all the Temp to Tmpx6. I pull down the dashboard for Temp and put the Tmpx6 in its place, etc..

For the display, I went back to the classic (local IP) site and change the display settings.

Ok, on my display modules (have 2) I have both my DT_Temp and Tempx9(PM2). In fusion and the classic dashboard I'm also displaying both temp probes. I was wondering where one would set which temp probe is used by the PM2 module to perform the ATC for the conductivity probe readings.

Edit: can see my setup and status here https://www.reeftronics.net/ja/jason2459/apex-status
spikes 4 times a day are due to return pump/skimmer shutdown for feeding for 30 minutes each time.

and here's my display module setup (Page 1 I've not touched any of the others)
Clock line Enabled
Probe line #1 Enabled
Condx9 Tempx9

Probe line #2 Enabled
DT_pH DT_Temp

jason2459
08/12/2015, 01:03 PM
Sorry OP I'm kind of hijacking this but at least it's on topic. Just want to make sure I'm setup right too and learning something new is always a good thing to me.

Jyetman
08/12/2015, 04:05 PM
How do I know the TempX5 is being used by the PM2 there are no settings in setup to confirm this?

slief
08/12/2015, 08:22 PM
How do I know the TempX5 is being used by the PM2 there are no settings in setup to confirm this?

If you have a temp probe connected to the PM2, that will be the default. I just checked all of the settings via the display. I dont see any way to assign a temp probe to the CondX probe or PM2. I think the PM2 will now use what ever temp sensor is available. If there is one connected to the PM2, it will use that. If there isn't, it will use the base unit. At least that is my guess but it should be confirmed with Neptune.

BlackTip
08/13/2015, 07:31 AM
I got a response back from Neptune regarding their first email to me. Initially, they asked me to move the Temp probe from the PM2 module to the main unit. I responded back and said that the manual states that the Temp probe should be connected to the PM2 module.

Their response was that they just want to confirm if changing the Temp compensation to 0 made a difference.

They didn't mention anything about the newest firmware and the Conductivity probe ability to work without temp compensation.

I am trying to get someone on the phone, but I am not able to get anyone to answer. I'll keep trying.

karimwassef
08/13/2015, 12:44 PM
I only have one temp probe. It's plugged into the PM2. I use it for everything...

It calibrates with the salinity probe. There's no issues.

Not sure why that doesn't work for you.