Uhhh well... @!?$ SG and ATC refrac

[Keachj06]

So my tank has been up and running for about 2 months. Got an ATC refractometer and calibrated using RODI like the instructions say had an SG of 1.026 for awhile added an ATO system and now it sits at approx 1.023. Got curious and bought some cal solution for the refractometer and well there's a pretty big dang difference between the two. I calibrated using the solution at 35PPT and now my salinity is sitting at approx 1.019... so my question is which is the true reading I noticed as soon as my salinity started to dive significantly over the weeks a 2 damsels died on me. Could it really be that the calibration method of RODI screwed me and now how should I approach bring salinity up rapidly but not enough to shock my fish, the issue about bringing it up rapidly is I have a torch coming tomorrow and I heard it needs to be in the 1.026 range for corals not so much fish .

 

[Reefing Madness]

Gotta use the calibration fluid.
Mix stronger batch of water, and swap it out, doing this for a couple days should bring you up.

 

[Randy Holmes-Farley]

What brand calibration fluid?

You an always make your own to double check.

 

[jason2459]

related thread to read through

https://www.reef2reef.com/threads/calibrating-a-refractometer.283740/page-3

 

[Rick.45cal]

You didn't say how big your tank is so I can't offer a volume to use, but if it was my tank, and my salinity was low, I would add 1 gallon of new saltwater (SG of 1.026) everyday to the tank, and let evaporation do the work for you. Test the salinity the next day before you add more saltwater. (I used 1 gallon as an example you should choose an appropriate volume for your tank size to add). The trick is to let the salinity come up slowly, evaporation will do that for you.

 

[Rybren]

You didn't say how big your tank is so I can't offer a volume to use, but if it was my tank, and my salinity was low, I would add 1 gallon of new saltwater (SG of 1.026) everyday to the tank, and let evaporation do the work for you. Test the salinity the next day before you add more saltwater. (I used 1 gallon as an example you should choose an appropriate volume for your tank size to add). The trick is to let the salinity come up slowly, evaporation will do that for you.

Or you could connect your ATO to a container of 1.026 SW and keep running it this way until you reach your target SG. It's the same idea, but it takes the guesswork out of how much SW to add.

As Randy alluded to, I would, however, double check the calibration of your refrac before making any adjustments to the tank.