How to lower salinity?

[jsmkmavity]

Heve you checked the refractometer? Sometimes they get dropped or something els happens to them and they go out of adjustment. This has happened to me. Test with a prepackaged sample available lots of places, or known saltwater mix, and/or check against another refractometer.

 

[Jimmythedestroyer]

Did a quick calc here for you - https://www.hamzasreef.com/Contents/Calculators/SaltwaterDilution.php - estimated 10 gal (could be less; you should calculate your real volume). To go from 1.033 sg to 1.026 sg you'd remove 1.12 cups of tank water, then add 1.12 cups of fresh RODI water to dilute. Pretty easy to correct in a small tank; this will be a big shift though so I would do a little today; run the calculator again tomorrow based on current salinity; wait a day, run it again based on that days salinity, until you get back in range. Don't move more than 0.003 in a day I think is a rough est for max

edit: oh and do this for sure ^^ calibrate

I know this is an old thread, but thank you for this. I just found out today my refractometer was way out of calibration. i thought i was at 1.022. Had LFS check and I'm at 1.033! I got some solution to calibrate, bottle said it should be at 35, it was at 25. Now that it is calibrated, i needed to know how much to replace with RODI to bring it down in my 100 gal setup. This calculator helps a lot! Thank you.