What am I missing? 1.028 salinity, Milwaukee Refractometer

[eddius-maximus]

I woke up this morning, had some coffee, checked my salinity. 1.028. I know some people have success running that salinity but that's a little too high for me. 

 

I recalibrate the Milwaukee Refractometer using the included 0.00 solution. Re-check. 1.028. I grab a jug and scoop out 3 cups of water to let my ATO compensate with RODI.

 

I check again. 1.028. Three more cups of water removed. 1.028. Three more cups of water. 1.028. 

 

At this point I'm starting to wake up and my brain is starting to function. Maybe the refractometer is busted despite it being exceedingly expensive and babied. So I check my upstairs anemone tank. 1.024. I check some freshly made saltwater. 1.025. So it appears to be working.

 

Why is it that even after 12 cups of water (130g total water volume) I'm unable to get this **** thing to read any different? At this point I'm just shooting for 1.027 but I'm afraid that this meter is fubared and I'm going to accidentally brick this tank!

 

What am I missing here? It's also probably worth mentioning that the included validation 1.025 SG solution is reading 1.028 as well. How bizarre! Although this could be an anomaly as it's fairly old solution and there have been instances where I've left it open on accident so evaporation could be an issue.

 

[Beaux]

I woke up this morning, had some coffee, checked my salinity. 1.028. I know some people have success running that salinity but that's a little too high for me. 
 
I recalibrate the Milwaukee Refractometer using the included 0.00 solution. Re-check. 1.028. I grab a jug and scoop out 3 cups of water to let my ATO compensate with RODI.
 
I check again. 1.028. Three more cups of water removed. 1.028. Three more cups of water. 1.028. 
 
At this point I'm starting to wake up and my brain is starting to function. Maybe the refractometer is busted despite it being exceedingly expensive and babied. So I check my upstairs anemone tank. 1.024. I check some freshly made saltwater. 1.025. So it appears to be working.
 
Why is it that even after 12 cups of water (130g total water volume) I'm unable to get this **** thing to read any different? At this point I'm just shooting for 1.027 but I'm afraid that this meter is fubared and I'm going to accidentally brick this tank!
 
What am I missing here? It's also probably worth mentioning that the included validation 1.025 SG solution is reading 1.028 as well. How bizarre! Although this could be an anomaly as it's fairly old solution and there have been instances where I've left it open on accident so evaporation could be an issue.
 

Try testing the water you are adding I sometime have a label fall off or the jugs got switched. Use tap water to see if you need to recalibrate it.
Do you have any salt creep that may have or is falling into the tank?

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[+Dogfish]

I would borrow a refractometer that is known to be in working order and check with it before changing the tank anymore.

Or

Get some new fluid.

1.025 cal solution reading 1.028 is not normal but as you say its old and may not be good.

12 cups is only 3/4 gallon

[eddius-maximus]

Thanks for the quick replies guys. I'll do all the things suggested. 

[Sierra Bravo]

130 gallons is 2080 cups.  The 12 cups you replaced is only about 1/2 of a percent of the volume - you aren't even making a dent.

 

[Sierra Bravo]

In case your refractometer checks out and is correct, here's a water change schedule to get it back to 1.025.  (Calculator address:  https://www.hamzasreef.com/Contents/Calculators/TargetSalinity.php )

Important:  Before you do anything you need to figure out how it got up to 1.028 to begin with.

[eddius-maximus]

So, my wife has been passively watching me scramble this morning. She just did the same math that Sierra Bravo did. Except she called me a dumbass at the end of it. Deserved. After emptying a few more cups I've been able to get the Refractometer to read 1.027 from 1.028 so it appears its all in working order and my tank is in fact sitting at 1.028.

 

So how did my salinity creep so high? Interesting dilemma. I stopped doing water changes 6 months ago and my tank has never looked better. But after some digging just now it would appear the large amounts of 2-part I dose (200ml of each) for all my SPS does indeed increase salinity. I had no idea. You add sodium carbonate and calcium chloride, and as the calcium carbonate is removed by corals, the sodium and chloride remain. I do empty quite a bit of SW out with my skimmer, I'd assume it would balance out. Apparently not. 

[Sierra Bravo]

It's probably been creeping up to that higher level for some time then.  I'd follow that water change schedule over the next three days and get it back slowly to where you want it.

[Sascha D.]

I agree with Sierra Bravo. The sg has  probably been creeping up over time with each water change. I personally only check salinity twice a year when I do a full check of water parameters or if I think something is amiss. I believe the danger in changing salinity is highest when increasing and decreasing isn't very risky. I would remove a gallon of tank water every 5-7 days and replace it with fresh RODI until the issue is resolved. You could probably do it faster, but there's no reason to take unnecessary risks. 

[jolt]

Indeed 2 part dosing causes salinity to creep up, I've seen it myself

And I agree with Sascha, take it a bit slow.  I would do that change over a couple of weeks.   I accidentally ran mine high for at least a month or two due to miscalibrated refractometer (bad calibration fluid).  Changed it slowly down and nothing bad happened.

[Sierra Bravo]

Here's a schedule based on changing 1 gallon a day.

[FarmerTy]

So, my wife has been passively watching me scramble this morning. She just did the same math that Sierra Bravo did. Except she called me a dumbass at the end of it. Deserved. After emptying a few more cups I've been able to get the Refractometer to read 1.027 from 1.028 so it appears its all in working order and my tank is in fact sitting at 1.028.
 
So how did my salinity creep so high? Interesting dilemma. I stopped doing water changes 6 months ago and my tank has never looked better. But after some digging just now it would appear the large amounts of 2-part I dose (200ml of each) for all my SPS does indeed increase salinity. I had no idea. You add sodium carbonate and calcium chloride, and as the calcium carbonate is removed by corals, the sodium and chloride remain. I do empty quite a bit of SW out with my skimmer, I'd assume it would balance out. Apparently not. 

Haha, I can picture her face while saying that! [emoji23] Glad you got it figured out bud!