salinity increases even with ATO

sgmccool · 03/31/2016, 02:40 AM

I have a Tunze Osmalator and I monitor salinity with an Apex.
Consistently the salinity increases even though the osmalator is keeping the water level stable (Level).

consistently it climbs every day by about .5 PPT.

I leave the tank for 8 days every other week so I need the stability without getting the wife involved. So in 8 days that's a swing from 35 PPT (1.0264) to 39 PPT (1.0294).

How do I get better stability?

Thanks
Sam

jason78 · 03/31/2016, 04:26 AM

Quote:

Originally Posted by sgmccool

I have a Tunze Osmalator and I monitor salinity with an Apex.
Consistently the salinity increases even though the osmalator is keeping the water level stable (Level).

consistently it climbs every day by about .5 PPT.

I leave the tank for 8 days every other week so I need the stability without getting the wife involved. So in 8 days that's a swing from 35 PPT (1.0264) to 39 PPT (1.0294).

How do I get better stability?

Thanks
Sam

Sam,

If you run a skimmer the ATO replaces the skimmed waist (has salt) with ro/di so that would explain you increase.

Ah64av8tor · 03/31/2016, 05:41 AM

Quote:

Originally Posted by jason78

Sam,

If you run a skimmer the ATO replaces the skimmed waist (has salt) with ro/di so that would explain you increase.

No... that would explain a drop in salinity (a drop in ppm) you cant make more salt by adding more water!

dendrite · 03/31/2016, 05:51 AM

If you're dosing significant amounts or two part daily that could be one explanation for increased salinity. Or if you mix salt and use it soon after mixing for water changes without it being completely dissolved in the bucket ,that could be another reason for increasing salinity in the tank

Bent · 03/31/2016, 07:08 AM

This may seem rudimentary and I don't mean to sound like I'm talking down to you but...

You do have fresh water in the ATO and not salt water right?

SouthFla · 03/31/2016, 09:44 AM

Quote:

Originally Posted by Bent

This may seem rudimentary and I don't mean to sound like I'm talking down to you but...

You do have fresh water in the ATO and not salt water right?

Exactly what I was thinking...that or heavy 2-part usage

sgmccool · 03/31/2016, 03:24 PM

So far none of the above, I don't dose 2 part. I use fresh RO/DI water for the top off, and This isn't right after a water change.

So why Am I getting an increase in salinity if I'm topping off with Fresh water?

andrewbram · 03/31/2016, 03:28 PM

Are you making sure that when you do a water Exchange the salt is dissolved completely and aerated

moatdaddy · 03/31/2016, 03:28 PM

What are you measuring your salinity with Sam?

DivingTheWorld · 03/31/2016, 03:29 PM

I see no scientific way the salinity can go up unless you're adding it. 2 part can definitely do it, especially Kent Tech M Mag. But without that, it's hard to say. Either your testing equipment is wrong (when was it last calibrated?), or your ATO contains salt.

sixpackgarage · 03/31/2016, 03:30 PM

I get an increase due to dosing, but your case is a mystery. It shouldn't magically increase unless there is input from some source like water changes.

sgmccool · 03/31/2016, 03:34 PM

Quote:

Originally Posted by andrewbram

Are you making sure that when you do a water Exchange the salt is dissolved completely and aerated

This is during a routine Auto Top Off not during water changes, and yes I mix my salt days in advance and run a pump to aerate.

sgmccool · 03/31/2016, 03:35 PM

Quote:

Originally Posted by moatdaddy

What are you measuring your salinity with Sam?

Using a Apex controller with a salinity probe

spifftempo · 03/31/2016, 03:35 PM

Sounds like you salinity probe isn't reading appropriately. If you give you probe a shake are there any air bubbles that are collecting on it?

If you place the probe in a cup of tank water outside the tank does it read differently?

sgmccool · 03/31/2016, 03:38 PM

Quote:

Originally Posted by DivingTheWorld

I see no scientific way the salinity can go up unless you're adding it. 2 part can definitely do it, especially Kent Tech M Mag. But without that, it's hard to say. Either your testing equipment is wrong (when was it last calibrated?), or your ATO contains salt.

Again not adding anything let alone 2 part. Calibrated apex salinity less than 30 days ago and even if it's out of cal it still doesn't explain the slow creep up.

ATO is pure fresh RO/DI water

DivingTheWorld · 03/31/2016, 04:29 PM

Quote:

Originally Posted by spifftempo

Sounds like you salinity probe isn't reading appropriately. If you give you probe a shake are there any air bubbles that are collecting on it?

If you place the probe in a cup of tank water outside the tank does it read differently?

+1, Apex Salinity probes are notoriously finicky. I had mine work correctly for one 4 month period, but other than that, it's always been off. I don't even bother with it anymore. If you want to know your true salinity, get yourself a Tropic Marin High Precision Hydrometer. They're not expensive and they're dead accurate.

kevin_e · 03/31/2016, 05:36 PM

I'd guess you're probe is no good. What does it read with a refractometer?

moatdaddy · 03/31/2016, 07:25 PM

i have a refractometer, hydrometer, and a Milwaukee digital reader. My milwaukee once zeroed will only hold the zero for a few days. Then it will need to be zeroed. I will go and check it with a refractometer. Hydro just sits on the shelf. My long winded point it a $20 refractometer may solve your problem.

slief · 03/31/2016, 08:28 PM

Quote:

Originally Posted by sgmccool

Again not adding anything let alone 2 part. Calibrated apex salinity less than 30 days ago and even if it's out of cal it still doesn't explain the slow creep up.

ATO is pure fresh RO/DI water

You need to test your salinity with a refractometer. As a very long time Apex user who uses a PM2 with salinity monitoring and 20+ year Neptune user, I can tell you from experience that the salinity probe should only be used for trends and fail safes. A properly calibrated refractometer is what you should be using for actual salinity values. If everything you are telling us in terms of top off and dosing is correct, then your salinity probe is either not calibrated properly or you have interence in your tank or in the way you have the probe wires routed that is causing erratic readings with your probe. That or your probe is faulty which is highly unlikely. If I had to guess, you didn't leave the new probe in the tank for several days to break in before calibrating it and or you didn't let it settle long enough when you calibrated. I let my probes settle for at least 10 minutes when calibrating and I also swirl them in the solution several times when calibrating. It's also important that place them in an area of the sump with high flow but no microbubbles.

That said, I am 100% certain your salinity isn't climbing like that if everything you say is correct and having helped many people with Apex issues and conductivity issues, I am 90% certain your not properly calibrated for one or both of the 2 reasons I mentioned and the other 10% would be interference related.

FWIW, unlike others, I have NO issues with my salinity probe calibration but I do calibrate every several months. I've been using the same PM2 and probe since the PM2 module was first released years back. It stays reasonably accurate when compared to my refractometer but again, I don't use it to check my salinity. I use it as part of my failsafes. For salinity checking, I use my refractometer which I calibrate with proper 1.026 calibration solution.

oscarcaldera · 05/09/2019, 03:14 PM

Coming late but I have an answer to this problem. When the salinity increases is because there is less fresh water in the tank. That happens when corals grow or when you add rocks, or any device in the water. If your corals grow, now you'll have less water in the tank and more corals, but the same amount of salt. Therefore the salt concentration increases.

outssider · 05/09/2019, 05:20 PM

Quote:

Originally Posted by oscarcaldera

Coming late but I have an answer to this problem. When the salinity increases is because there is less fresh water in the tank. That happens when corals grow or when you add rocks, or any device in the water. If your corals grow, now you'll have less water in the tank and more corals, but the same amount of salt. Therefore the salt concentration increases.

It increased 4ppt in 8 days.....no corals are going to grow that fast

nor.cal2000 · 05/10/2019, 11:37 AM

Get the Milwaukee salinity tester MA887. Works perfect, is very accurate and worth the investment for an important parameter.

Vinny Kreyling · 05/10/2019, 11:53 AM

Have a friend with a refractometer to check it out?

03/31/2016, 02:40 AM	#1
sgmccool Registered Member Join Date: Nov 2014 Posts: 16	salinity increases even with ATO I have a Tunze Osmalator and I monitor salinity with an Apex. Consistently the salinity increases even though the osmalator is keeping the water level stable (Level). consistently it climbs every day by about .5 PPT. I leave the tank for 8 days every other week so I need the stability without getting the wife involved. So in 8 days that's a swing from 35 PPT (1.0264) to 39 PPT (1.0294). How do I get better stability? Thanks Sam

03/31/2016, 07:08 AM	#5
Bent I got nothin' Join Date: Nov 2004 Location: The anals Posts: 6,420	This may seem rudimentary and I don't mean to sound like I'm talking down to you but... You do have fresh water in the ATO and not salt water right? __________________ Quitters never lose. [QUOTE=CStrickland]Who gets mad at a starfish?[/QUOTE] Current Tank Info: 75g DT, 30G refugium, 10g chaeto tank, 50g stock tank basement sump

03/31/2016, 03:29 PM	#10
DivingTheWorld Registered Member Join Date: Sep 2013 Location: San Ramon, CA Posts: 1,963	I see no scientific way the salinity can go up unless you're adding it. 2 part can definitely do it, especially Kent Tech M Mag. But without that, it's hard to say. Either your testing equipment is wrong (when was it last calibrated?), or your ATO contains salt. __________________ Current Tank Info: LeeMar Rimless (40x24x22), ATI 8x39 Dimmable w/Reefbrite XHO, 2x Vortech MP40w QD w/ Battery Backup, Apex Gold, Trigger Systems Ruby30S, Reef Octopus POV-DC1 w/Auto Waste Collector

03/31/2016, 03:30 PM	#11
sixpackgarage reef mechanic Join Date: Jun 2015 Location: Phoenix, AZ Posts: 819	I get an increase due to dosing, but your case is a mystery. It shouldn't magically increase unless there is input from some source like water changes. __________________ my build: http://www.reefcentral.com/forums/showthread.php?t=2512689 my fuge thread: http://reefcentral.com/forums/showthread.php?t=2523500 Current Tank Info: DSA NEO 65G reef powered by Kessil

05/10/2019, 11:53 AM	#23
Vinny Kreyling Registered Member Join Date: Nov 2002 Location: Miller Place, NY Posts: 7,206	Have a friend with a refractometer to check it out? __________________ 250 gallon mixed reef, 2 Reefbreeder's Photon V 2, Deepwater BLDC 12, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.

03/31/2016, 05:51 AM	#4
dendrite Registered Member Join Date: May 2013 Location: denver Posts: 493	If you're dosing significant amounts or two part daily that could be one explanation for increased salinity. Or if you mix salt and use it soon after mixing for water changes without it being completely dissolved in the bucket ,that could be another reason for increasing salinity in the tank

03/31/2016, 03:24 PM	#7
sgmccool Registered Member Join Date: Nov 2014 Posts: 16	So far none of the above, I don't dose 2 part. I use fresh RO/DI water for the top off, and This isn't right after a water change. So why Am I getting an increase in salinity if I'm topping off with Fresh water?

03/31/2016, 03:28 PM	#8
andrewbram Registered Member Join Date: Apr 2007 Location: Colorado Posts: 337	Are you making sure that when you do a water Exchange the salt is dissolved completely and aerated

03/31/2016, 03:28 PM	#9
moatdaddy Registered Member Join Date: Mar 2006 Location: Panama City beach florida Posts: 848	What are you measuring your salinity with Sam?

03/31/2016, 03:35 PM	#14
spifftempo Registered Member Join Date: Jan 2009 Posts: 65	Sounds like you salinity probe isn't reading appropriately. If you give you probe a shake are there any air bubbles that are collecting on it? If you place the probe in a cup of tank water outside the tank does it read differently?

03/31/2016, 05:36 PM	#17
kevin_e Registered Member Join Date: Jun 2013 Posts: 1,083	I'd guess you're probe is no good. What does it read with a refractometer?

03/31/2016, 07:25 PM	#18
moatdaddy Registered Member Join Date: Mar 2006 Location: Panama City beach florida Posts: 848	i have a refractometer, hydrometer, and a Milwaukee digital reader. My milwaukee once zeroed will only hold the zero for a few days. Then it will need to be zeroed. I will go and check it with a refractometer. Hydro just sits on the shelf. My long winded point it a $20 refractometer may solve your problem.

05/09/2019, 03:14 PM	#20
oscarcaldera Registered Member Join Date: Oct 2015 Location: New York Posts: 4	Coming late but I have an answer to this problem. When the salinity increases is because there is less fresh water in the tank. That happens when corals grow or when you add rocks, or any device in the water. If your corals grow, now you'll have less water in the tank and more corals, but the same amount of salt. Therefore the salt concentration increases.

05/10/2019, 11:37 AM	#22
nor.cal2000 Registered Member Join Date: Jul 2016 Posts: 10	Get the Milwaukee salinity tester MA887. Works perfect, is very accurate and worth the investment for an important parameter.