Lowering Salinity from 36.59 to 35 / Help Please

[exnisstech]

Ok, perhaps the Hanna fluid is faulty.

I've used fluid with different lot numbers with the same results. I've read of others having the issue as well. I quit using them for anything more than an occasional check and if it shows 1.024 it means 1.026 but i really don't trust them.

 

[Randy Holmes-Farley Verified Community Expert]

Random question and i assume this is not a legitimate concern based on all the replies so far. But if i replace too much salt with fresh water all at once. Wouldnt that drop something like alkalinity by several points?

If you drop salinity from 36 ppt to 35 ppt, alk will only drop from say, 8 dKH to 7.8 dKH.

 

[mcarroll]

Do I have a magical refractometer, or can anyone float a hypothesis why everyone else's refractometers need continuous recalibrating?

My Marine Depot refractometer from ~2005 is still basically on its original calibration.* Reads RODI correctly, reads calibration fluid (American marine and Brightwell) correctly. All I've done is use it and put it back in the case (dry) when done. It does not change on its own or "from usage".

Am I babying it??? Are they just not making them "like they used to"? I'd be back to using a hydrometer if my refractometer acted like that.

* It did get purposefully miscalibrated, then recalibrated once about 10 years ago.

 

[BryanM]

Perfect, thank you. I took about 2 cups out earlier prior to even having a plan lol. I’m gonna plan to fill the ato reservoir more regularly and test. Ty

in 220 gallons you'll need more than a cup or two, I'd start with a gallon, but I bet it takes 5.

Just let the ato replace it with rodi and test again in a couple hours.

 

[vetteguy53081]

Do I have a magical refractometer, or can anyone float a hypothesis why everyone else's refractometers need continuous recalibrating?

My Marine Depot refractometer from ~2005 is still basically on its original calibration.* Reads RODI correctly, reads calibration fluid (American marine and Brightwell) correctly. All I've done is use it and put it back in the case (dry) when done. It does not change on its own or "from usage".

Am I babying it??? Are they just not making them "like they used to"? I'd be back to using a hydrometer if my refractometer acted like that.

* It did get purposefully miscalibrated, then recalibrated once about 10 years ago.

When was it last calibrated?