Need ppl with Neptune Salinity Conductivity probe expertise

[ZoWhat]

I'm frustrated as all get out....

I have the Neptune salinity probe. My sump is in the basement. I have the PM2 mod and probe setup to monitor the SG in my sump.

Problem is I've recalibrate this dag gone probe i know 30 times. Followed overnight probe dryness, matched 53k solution to exact tank temp ...every step to the "t"

It will read 34.9 upon being put in a probe holder as far away from any microbubbles in the sump.

The 34.9 is pretty spot on what my calibrated refractometer says my tank SG is.

I'll get a 34.9 reading initially for the first 30mins BUT THEN the readings slooooooowly far by 0.1 at the rate of 0.1 every 20-30mins

By morning what was a 34.9 reading drops but levels out at 29.4ish

Extremely frustrating.

What is this slow falling of a reading an indication of?
> Microbubble buildup?
> Stray voltage?
> Too much flow?
> Not enough flow?

I'm about to fall on the probe like a Japanese sword and commit suicide.... so I need answers before I take $350 worth of equipment and throw it against a concrete basement wall.

Help....

 

[ZoWhat]

UPDATE:

did a lot of reading on Neptune's site and read that this probe measures the conductivity of the water in relation to the the amount of salinity (salt) in the water.

It's reeeeeeally not a true direct indicator of SG at 1.026 ~ 35.0

It went on to say it very hard to match conductivity (that this probe measures) to match exactly SG in the water

It's not a SG monitor probe.

It's a conductivity probe to set up alarms that if the conductivity # goes higher than = your SG is higher. Vice versa with #s going lower

I'm renaming the probe as "CONDCT" and whatever siemens/meter of conductivity it's measuring.... thats the # I'm living with ... and will watch that # as it rises or fall.

Rise in CONDCT = SG is getting higher and need to add RODI

Falling CONDCT = SG is faling into hyposalinity and Time to see why the water is less salty.... faulty flooding ATO (?)

Soooo, again it's extremely hard to have this probe lay dead nuts on top of true SG #s bc its measuring conductivity NOT SG.

I know accept my conductivity of 29.x is telling me I'm around 1.024, .025, .026ish

Scratching erasing the thought 29.x should be 6.x higher to match 35ish SG

.

 

[AydenLincoln]

This is happening to me too! I’m contacting Apex. Do you use a salinity stabilizer? For me that helped get an accurate reading until it didn’t lol.

 

[Tuan’s Reef]

I bought the Apex EL just so i can avoid the apex's salinity probe and orp probe. lol Following along to see if there is a solution for your problem.