Neptune Apex Conductivity Probe Reliability

[Mark Lang]

For the 2nd time in a couple weeks, my Neptune Apex Conductivity probe went haywire. This probe is just over two weeks old. It's been caibrated at least 2x.

I really like the idea of continuous monitoring. But the reliability of readings on these Neptune probes makes me want to try another solution on my Neptune.

Is there a good alternative that I could try on my Neptune system that might provide more reliable readings?

Here is a chart of reading prior it going off the rails... again not very useful. My salinity is 35.0 - 35.1 ppt every time I check it with my Hanna probe (of course calibrated to 35ppt).

 

[Waters]

While some have very good luck with it, I have always found it to be unreliable, and use it strictly to watch for swings. It doesn't take much to throw it out of whack....air bubbles being a pretty common reason. If I remember, there are some threads here that talk about what to do to get it to read properly but I have never messed with it.

 

[Chrisss]

I was all about the conductivity when I first started out thinking it was the most needed thing on my tank (2014 ish). However, the probe was the most unreliable thing I ever tried out. Going from 30-35-37 all within a hour. I eventually just ignored all readings and used it as a "is there salt in this location" type of thing and put it in the return section so when it reads 0/20 (I forgot what empty was) I would know there is no longer water there.

I don't think any solution will be perfect that's just the nature of the probes. I did try getting new ones/calibrating every 6 months and no luck.

Personally once you get going, salinity is the last thing you worry about. You will understand your tanks needs more / when to add more salt / when to add more rodi etc... eventually will become one of your easier parameters to control

 

[FishTruck]

LOL, I dropped mine in and it read 33 which was coincidentally spot on. Then, I decided to turn it upside down - and a couple bubbles came out - and was reading 46. So... I figured out how to recalibrate it - keeping the probe upside down (no bubbles). For this, you need to make a larger amount of 35 ppt water in a big enough container to have the probe upside down and flooded during calibration. This is a pain... I wish I could just tell it what number I want it to read and not have to calibrate to exactly 35 ppt every time.

I have a another conductivity probe and controller - allegedly higher quality and reliable enough to use to control parts of my system. And... it reads great for a couple of weeks, then the conductivity will start to drop - (35-31-29) which means it is dirty. Dipping and swirling it in lemon juice does the trick. It seems less prone to get bubbles in it - so it does not do the sudden jump up - but still requires fussing every couple of weeks- and I have learned to assume the probe needs attention and not that my tank suddenly got flooded with RO water.

Oh.. and a "real" industrial conductivity controller and probe will set you back about 700 dollars. I decided not to go down that road! I have heard of other probes being wired into the neptune and working better - but, you have to check the wiring and the K constant to make sure the probe is correct.

 

[Roosterjack]

Not sure how my Hanna pocket checker is early always spot on despite being subject to over a year of (ab)use but a brand new Neptune probe is as reliable as a campaign promise Right out of the box.