Randy Holmes-Farley
Reef Chemist
View Badges
Staff member
Super Moderator
Ultimate Member
Partner Member 2027
Excellence Award
R2R App User
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
If you using a brine refractometer to measure sg = 1.009, there’s no perfect solution, either calibrating with 35 ppt or ro/di. Both Will be off, but both are probably close enough. If I had to pick, I’d use ro/di