Proper Conductivity Readings?

[cm11599ps]

What are you guys keeping the conductivity readings at? Mine go anywhere from 34.9 up to 36.7 or so. I'm only talking about the readings using the PM2 and conductivity probe, not a refractometer.

 

[cm11599ps]

Anyone?

 

[md ca]

Mine vary a lot also. I use it as an indication that SG is seriously wrong, but I mostly ignore the day to day fluctuations.

 

[Jocko]

Hmm mine doesn't vary like that. Do you have anything near it that might be giving off stray current? If you look at the graph for conductivity, do you see any pattern to the fluctuation? Maybe you could correlate that to something in your tank like a heater or pump being on at certain times.

 

[cm11599ps]

Mine stays pretty consistent. What readings are you guys getting though? Mine is usually around 36.

 

[Jocko]

It's not entirely clear to me what you're looking for here. I initially thought you were complaining about the reading from your conductivity probe fluctuating, but I guess that's not it? Do you just want to know what salinity people run their tanks at? Or are you trying to figure out a way to keep the salinity more constant with ATO?

 

[md ca]

I have not been able to get consistent or accurate readings from my conductivity probe. Is there a way to make them more reliable? I have calibrated and recalibrated.

 

[ScottB]

Mine has wandered for a time, but just yesterday I calibrated with 447us solution, and made a temp correction to keep it in line with my refractometer, and it is stable and steady as I would expect it to be. I only use it for trending, and rely on my refractometer, but it should be reasonably predictable and steady.

 

[cm11599ps]

Thanks guys. What number range are you generally getting? I've found that 36.6 seems to be about 1.026 for me.

 

[Gougeman]

Definitely check for stray current or magnetic field sources near the probe. Mine was wandering from 33 to 36 and I couldn't figure out why until I looked at the history graph and noticed it was perfectly stable at night. It turned out that I had a flourescent light bulb too close to the probe and whenever it was on things got wonky. I moved the probe further away from the bulb and it has been +-0.1 ever since.