Learned a valuable lesson today.

GoReefin · Apr 9, 2021

Have been doing weekly water changes for 6 months with the tank looking great corals happy etc. Then noticed my red bubble tip anemones started uprooting and moving around with several splitting. So I checked salinity was "normal" 1.026 and was like hmm checked my calcium was 380 and my DKH was 7 yikes. So I bought a hydrometer and low and behold my salinity was 1.23! So I checked my calibration of my refractometer and it was off by the same amount.

Lesson of the story is calibrate your refractometer every time you do a water change to avoid this mistake. Thankfully nothing is dead but just unhappy. Will be doing a few water changes a few days apart to get the salinity back in check.

Fish_Sticks · Apr 9, 2021

Nice lesson

also worth mentioning to replace calibration fluid.

RyanS · Apr 9, 2021

GoReefin said:
Have been doing weekly water changes for 6 months with the tank looking great corals happy etc. Then noticed my red bubble tip anemones started uprooting and moving around with several splitting. So I checked salinity was "normal" 1.026 and was like hmm checked my calcium was 380 and my DKH was 7 yikes. So I bought a hydrometer and low and behold my salinity was 1.23! So I checked my calibration of my refractometer and it was off by the same amount.

Lesson of the story is calibrate your refractometer every time you do a water change to avoid this mistake. Thankfully nothing is dead but just unhappy. Will be doing a few water changes a few days apart to get the salinity back in check.

Just start adding a little salt daily until it hits your target. wc not needed to get it up.

Garf · Apr 9, 2021

How did you check the calibration of the refractometer? DONT use RODI. It can be way off.

iMi · Apr 9, 2021

I agree. Always use a calibration liquid on a refractometer. I check mine every couple of weeks.

fachatga · Apr 9, 2021

I love all the tips I pick up here. Being so new and knowing nobody who does this. Now I’ll make sure to be watching for that.

GoReefin · Apr 9, 2021

Garf said:
How did you check the calibration of the refractometer? DONT use RODI. It can be way off.

Used distilled water

Fish_Sticks · Apr 9, 2021

GoReefin said:
Used distilled water

You might wanna buy some 35ppt refractometer calibration solution

Garf · Apr 9, 2021

GoReefin said:
Used distilled water

Same problem. You need to use a calibration standard at around the value you’re trying to measure. There’s a simple DIY one you can make using table salt and RODI.

GoReefin · Apr 9, 2021

Fish_Sticks said:
You might wanna buy some 35ppt refractometer calibration solution

Yeah, I should totally buy some! Hitting up amazon. Do you happen to know what brand you use?

Fish_Sticks · Apr 9, 2021

GoReefin said:
Yeah, I should totally buy some! Hitting up amazon. Do you happen to know what brand you use?

I have no idea :/ as long as its fresh and new it should be good

GoReefin · Apr 9, 2021

Garf said:
Same problem. You need to use a calibration standard at around the value you’re trying to measure. There’s a simple DIY one you can make using table salt and RODI.

Yeah will be buying some solution. For the time being my refractometer was off by what my hydrometer was showing. It should be calabrated pretty close to correct between the two. I'll be buying solution today.

GoReefin · Apr 9, 2021

I found this solution on amazon will be purchasing today.

iMi · Apr 9, 2021

GoReefin said:
I found this solution on amazon will be purchasing today.

This is what I use as well. Works well.

GoReefin · Apr 9, 2021

iMi said:
This is what I use as well. Works well.

Glad to hear this!

arking_mark · Apr 9, 2021

The 12 Commandments of Reef Keeping

Nothing good happens fast in a reef tank Triple-check before you believe any observations or make any changes to your tank Only make one change at a time in your reef tank Use the right tool for the right job Only dose what you can test for Don't chase #s, chase stability. When altering the...

www.reef2reef.com

Might need to update this one...

Triple-check before you believe or make any changes to your tank

To...

Triple check before you believe any observations or make any changes to your tank

Nick Rose · Apr 9, 2021

Similar situation happened to me. But in a different way. I have been using a Hanna Salinity checker. It’s been calibrated once. I check it with a calibrated refractometer and it was matching. But the calibration solution(brightwell) is 2 years old so decided to get a new bottle. I calibrate it with the new bottle and then test the tank water and it reads 39ppt. So I then decided to calibrate the Hanna and that shows 36ppt. I went to the LFS and they read 39ppt. Then I went onto Amazon and bought two over calibration solutions and they read 39ppt.

Don’t know how long the tank has been this way. It could be a year, half a year, a few months. The kicker is that everything is doing well. SPS is incrusting like crazy. Wouldn’t the new SPS coming from a 35ppt system be dead not incrusting in a 39ppt system.

I might make a new thread. Don’t want to hijack this thread.

Ratsinmyhead · Apr 10, 2021

Garf said:
Same problem. You need to use a calibration standard at around the value you’re trying to measure. There’s a simple DIY one you can make using table salt and RODI.

Calibration solution can also be off. I bought a bottle off Amazon or eBay. Bottle was sealed and well within the expiration date. I forget how much it was off by and the brand but it was for sure off. Now I just test the water I get from my lfs whenever I get a new fish or coral and calibrate off of that. Figure with thousands more invested in livestock and replacing lost water everyday they keep a very close eye on it.