Wild salinity swings (Doh!!)

[y-not]

I've been chasing my tail over this issue for a few months.

I've got a Red Sea Max 250 with an Apex controller w/a salinity probe and an ATO.

I've been watching my salinity swing from 33ppt to 35ppt (ideal is 35ppt).
Whenever I see it drop, I check the Salinity with my refractometer and sure enough, regardless of what Apex is saying, it's setting right at 1.026 (35ppt).

WTH...
I've been racking my brain over this.
I know that there is an issue with the probe cables not running side by side. Keep them at a 90 degree crossing if they must, etc...

I've made sure that all the probe cables are as far away from one another as possible. At the closest point, they are within 3 inches of each other. This is right at the control boxes. Not alot I can do about that.

Then last night, I was checking the skimmer and I noticed that my ATO feed line had shifted and was feeding fresh water right into the area that the over flow goes into. My salinity probe sits almost directly behind the over flow.

Doh!! :blush:

Every time the ATO kicks in, the Apex reports that the salinity has dropped. Then shortly after, the salinity goes back up (according to the Apex).

Now...if I try and calculate how much time I've spent trying to figure out this riddle, I'll lose what's left of my mind. :sick:

 

[jennm]

:doh:

 

[picoreefguy]

dont you love silly mixups like that.

 

[jef4y]

I don't know why people obsess with salinity monitoring. There are really only 2 things that will affect salinity. Evaporation of water or adding excessive RO. If you have a decent ATO and measure your salt properly during water changes, it will never change.

The only time I ever bothered checking salinity was when I was acclimating something. And every time it was the same. 1.026...

 

[y-not]

JeF4y;903392 wrote: I don't know why people obsess with salinity monitoring. There are really only 2 things that will affect salinity. Evaporation of water or adding excessive RO. If you have a decent ATO and measure your salt properly during water changes, it will never change.

The only time I ever bothered checking salinity was when I was acclimating something. And every time it was the same. 1.026...

It's a control thing Jeff! :yes:

The Apex was freaking me out.
All the while, I knew that what I was putting in during WC was 1.026 and my refractometer always read the same, 1.026. The Apex readings were bouncing around.

http://www.atlantareefclub.org/forums/photoplog/images/7119/medium/1_Salinity.JPG" alt="" />

I had to figure out why. It was a riddle that just HAD to be answered. :tongue:

 

[johniii]

That happens to me as well
Sent from my XT912 using Tapatalk 4

 

[grouper therapy]

Same here. I have to know why.

 

[y-not]

grouper therapy;903399 wrote: Same here. I have to know why.

I know. It drives me nucking futs sometimes.
It's stupid little stuff like this that causes my wife to think I love the tank more than her.

I keep telling her that issues with the tank, I can figure out and fix. Her issues are a whole different story. :wow2:

 

[1percula]

I have practically given up on the salinity probe. It doesn't stay calibrated and I don't have the hours to sit there to keep programming and reprogramming it. As for why to monitor the salinity, you can always have an ATO go wild or a miscalculation with water changes that can leave your salinity out of whack. I need the Apex because I work a lot of hours and I am trying to minimize my time working on the tank and spend my time enjoying the tank. I am in favor of anything that reduces the amount of monitoring necessary to run it.

 

[clay4au]

2 part dosing is actually salt based and can cause the salinity to creep up over time.
Normally through skimming and ATO this is a very slow process and is easily corrected through consistent water changes, but if you dose heavy and are slack on water changes just keep it in mind

 

[darrrenjmartin]

Salinityisoftenexpressedaspartsperthousand(ppt)whichisapproximatelyequalto grams of salt per liter of solution. However, salinity is the sum weight of many differ- ent elements within a given volume of water; not just sodium from sodium chloride. In the 1970’s, salinity was redefined as the conductivity ratio of a water sample to a standard potassium chloride (KCl) solution.

The Salinity Sensor measures the electric current through a solution between the two platinized platinum electrodes in the Salinity Sensor Probe. The current through the solution is due to the movement of ions, so the higher the concentration of ions in the solution, the higher its conductivity. A voltage (AC) is applied across the two elec- trodes in the tip of the probe and the measured current is proportional to the conduc- tivity of the solution.

 

[darrrenjmartin]

Salinity is often expressed as partsperthousand(ppt)whichisapproximatelyequalto grams of salt per liter of solution. However, salinity is the sum weight of many differ- ent elements within a given volume of water; not just sodium from sodium chloride. In the 1970’s, salinity was redefined as the conductivity ratio of a water sample to a standard potassium chloride (KCl) solution.

The Salinity Sensor measures the electric current through a solution between the two platinized platinum electrodes in the Salinity Sensor Probe. The current through the solution is due to the movement of ions, so the higher the concentration of ions in the solution, the higher its conductivity. A voltage (AC) is applied across the two elec- trodes in the tip of the probe and the measured current is proportional to the conduc- tivity of the solution.

Anything reactive added or subtracted will cause a reaction. part of a reaction will result in The exchange in free IONs and/or e-. This will result in a of change the conductivity of the solution during the reaction. The probe will detect this reaction. If you had a ORP , which is also a electrostatic function, you may be able to see this swing also.

Some of this reaction may be exothermic( heat). Try a chilling a small sample ato to near freezing in a cooler. and see if the swing is reduced or changed.

A wealth of misinformation

 

[acroholic]

Dosing with magnesium chloride and/or calcium chloride (salts) will raise the specific gravity of your water.

I don't trust salinity probes. Digital Aquatics sold one for the ReefKeeper controllers, and they are junk. Maybe for use as a toy, but not to gauge and adjust my specific gravity from. Get an ocular refractometer to do that. Or if you want something electronic, get a digital seawater refractometer, like this one rom Milwaukee Instruments. I've had one for a couple years and love mine.

 

[y-not]

Acroholic;903601 wrote: Dosing with magnesium chloride and/or calcium chloride (salts) will raise the specific gravity of your water.

I don't trust salinity probes. Digital Aquatics sold one for the ReefKeeper controllers, and they are junk. Maybe for use as a toy, but not to gauge and adjust my specific gravity from. Get an ocular refractometer to do that. Or if you want something electronic, get a digital seawater refractometer, like this one rom Milwaukee Instruments. I've had one for a couple years and love mine.

http://www.scical-plus.com/ma871.html?gclid=CLO7lKjljLoCFc5FMgodPXsAiA">http://www.scical-plus.com/ma871.html?gclid=CLO7lKjljLoCFc5FMgodPXsAiA</a>[/QUOTE]


Trust the probe?
Good grief no!
Use it as a point of reference? Oh yeah! Depend on it, NOT.

 

[ralph atl]

Acroholic;903601 wrote: Dosing with magnesium chloride and/or calcium chloride (salts) will raise the specific gravity of your water.

I don't trust salinity probes. Digital Aquatics sold one for the ReefKeeper controllers, and they are junk. Maybe for use as a toy, but not to gauge and adjust my specific gravity from. Get an ocular refractometer to do that. Or if you want something electronic, get a digital seawater refractometer, like this one rom Milwaukee Instruments. I've had one for a couple years and love mine.

http://www.scical-plus.com/ma871.html?gclid=CLO7lKjljLoCFc5FMgodPXsAiA">http://www.scical-plus.com/ma871.html?gclid=CLO7lKjljLoCFc5FMgodPXsAiA</a>[/QUOTE]



as stated, those probes are useless....and anytime ro is added, salinity will go down a tad, anytime Calcium and/or mag is added salinity will rise...

 

[acroholic]

mysterybox;903814 wrote: as stated, those probes are useless....and anytime ro is added, salinity will go down a tad, anytime Calcium and/or mag is added salinity will rise...

I'd use a swing arm hydrometer before I'd use a digital salinity probe, ugh!