ok need your opinion.

I have 35 ppt calibration fluid i use for my refractometer. works great for the reef. However I am treating my fish with hypo salinity. If i check my meter with RO water it is a little ways below 0. so my thought was to calibrate it for the RO water since it is closer to the 1.008 i am shooting to get my salt to for my fish, rather than 1.026 (35)ppt that my calibration solution is for. What are your thoughts. My reads about a .003 difference between the two calibration points. so should I leave it calibrated with the solution at 35 ppt or calibrate it with RO water at 0 to get the most accurate measure at 1.008

Thanks

Jarrod