Refractometer off big time! Help

[coronarex]

I just recalibrated my refractometer. Tested the salinity of my tank and it is 1.022. This explains a lot. Considering the struggles I’ve been having. My tank is almost a year old. Surprising my corals are doing well but I have killed a lot. I’ve been struggling w my parameters and this is def the answer to my problems I believe. Should I do a water change and correct it in one go or slowing bring it up over several weeks. Thanks

 

[cracker]

I "think " You need to bring it up slowly. Either do a modest water change with new water with proper salinity now that the refractometer is set correctly. this would raise it slowly. Or the easy way is to let it rise by evaporation
(no top off) until t he salinity matches what You want. Honestly that's not a big difference but I understand it will throw off test results.
I just wait till the water evaps & then do the water change with the same salinity. Let us know how it turns out.
Disclaimer I'm "not" one of the more knowledgeable Folks around here ! lol

 

[Dennis McGrath]

I had mine that was off with a batch of saltwater that I was making, (measure the same amount of salt as normal), it was reading 1.023. Then I tested my tank, it was also reading 1.023. I recalibrated it and low an behold it was lower than the baseline on the scale. Retested and read 1.026 as normal.

 

[coronarex]

I "think " You need to bring it up slowly. Either do a madest water change with new water with proper salinity now that the refractometer is set correctly. this would raise it slowly. Or the easy way is to let it rise by evaporation
(no top off) until t he salinity matches what You want. Honestly that's not a big difference but I understand it will throw off test results.
I just wait till the water evaps & then do the water change with the same salinity. Let us know how it turns out.
Disclaimer I'm "not" one of the more knowledgeable Folks around here ! lol

Wow thank you. I would’ve never thought to do it that way.

 

[MTBake]

I let evaporation do the work in cases like this. Once the tank gets back to where you want it, top it off with the same salinity water and you should be good to go.

You can also do water changes with normal salinity water. I would try to avoid raising more than .002 per day doing water changes.

Really up to you. I think the evaporation route is easiest and safest myself.

 

[Dennis McGrath]

In the past, when I had an issue with low salinity, I did a series of smaller water changes with water at 1.030 a few times, to bring it up to 1.026

 

[Crabs McJones]

You can do a series of small water changes to bring it back up. Or you can turn off your ATO and top off with saltwater instead of freshwater until your salinity is where you want it.

 

[FoxyFace]

I had an issue of the salinity creeping high. I'd really like a cheap pen salinity tester but they're so pricey.

 

[coronarex]

Tha

I let evaporation do the work in cases like this. Once the tank gets back to where you want it, top it off with the same salinity water and you should be good to go.

You can also do water changes with normal salinity water. I would try to avoid raising more than .002 per day doing water changes.

Really up to you. I think the evaporation route is easiest and safest myself.

i agree that it’s the safest and easiest, thank u fam

 

[Rcpilot]

Sometimes cheap and simple works just fine.
https://www.amazon.com/MECO-Aquariu...ocphy=9011833&hvtargid=pla-348108632296&psc=1

I always used a floating glass hydrometer and a cylindrical flask. Take a sample right out of the sump and gently place the hydrometer in. Set on the counter and read. They're $8 and they never need calibration. If it worries you, buy a new one every 6 months. Still a heckuva lot cheaper than an electronic device with questionable calibration and circuitry.

I would agree with letting it evaporate slowly. Top off with saltwater for a few days or a week until you're back to normal.

 

[chipmunkofdoom2]

S = 30 ppt (1.022 sg) is not ideal, but I don't personally think this is the cause of all of your problems. Some reefs in the wild are between S=32 ppt and S= 33 ppt. S=30 ppt is lower than we'd like, but it's not that far off from what some wild reefs are.

First thing to do is make sure your refractometer is working. How did you calibrate it, with freshwater or with a commercial refractive index standard? If it was with the former, I would ignore the result until you can get the latter. Next, test a few times in a row and make sure you get the same result again and again. Back when I used a refractometer, I would not only have to calibrate every time, I would have to calibrate twice to get stable readings. I would calibrate once, rinse, and find that the calibration was off. After calibrating again, the reading was consistent. Only then could I test the tank water and get consistent results. I've since moved to an American Marine Pinpoint Salinity monitor and will never go back to a refractometer of any type.

If the reading is accurate, don't make any sudden changes. It likely took a while for your tank to get this way, and bringing the salinity up too fast will cause more stress. I would simply add saltwater as your top-off for the next few days, as suggested by a few other members, and monitor the salinity accordingly.

 

[Chris Wells]

I would verify calibration method and accuracy first like @chipmunkofdoom2 suggests.

I almost reacted to this exact same thing by calibrating to RODI water at 0 instead of calibration fluid at 35ppt, when the refractometer directions specifically said to only use calibration fluid at 35ppt. Also, if you have temperature type refractometer, give it 15-30s to adjust to temp before reading.

Chris

 

[coronarex]

I have taken all of your recommendations, which I appreciate greatly. I use a refractometer and recalibrated it with a liquid product that I purchased on Amazon. The liquid has a salinity of 35 ppt. I am super ocd so I checked it rinsed it, waited, rechecked too many times to count. I am confident I am getting a consistent reading. Every time I check my tanks salinity I will do this. I decided to just let the tank evaporate up to my desired salinity. It took about 5 days. We are good

 

[beaslbob]

Sometimes cheap and simple works just fine.
https://www.amazon.com/MECO-Aquariu...ocphy=9011833&hvtargid=pla-348108632296&psc=1

I always used a floating glass hydrometer and a cylindrical flask. Take a sample right out of the sump and gently place the hydrometer in. Set on the counter and read. They're $8 and they never need calibration. If it worries you, buy a new one every 6 months. Still a heckuva lot cheaper than an electronic device with questionable calibration and circuitry.

I would agree with letting it evaporate slowly. Top off with saltwater for a few days or a week until you're back to normal.

Long time ago I read a review on swing arm hydrometers. Seems they are pretty accurate (even if temperature dependent). But you do have to keep then clean and make sure the swing freely.

my .02

 

[Rcpilot]

I have taken all of your recommendations, which I appreciate greatly. I use a refractometer and recalibrated it with a liquid product that I purchased on Amazon. The liquid has a salinity of 35 ppt. I am super ocd so I checked it rinsed it, waited, rechecked too many times to count. I am confident I am getting a consistent reading. Every time I check my tanks salinity I will do this. I decided to just let the tank evaporate up to my desired salinity. It took about 5 days. We are good

AWESOME!! Glad it was a reletively easy fix.

 

[vetteguy53081]

Calibrate. Easy method.... Solution and a small screwdriver