Salinity woes

[esmithiii]

Ok, I broke down and bought a refractometer since my salinity monitor is acting up. I used it and my tank is reading 1.029, which on a 55 means it is about 6 gal short. My bobbing-type hydrometer shows 1.027, my salinity monitor shows 1.026. I am stumped! I checked the calibration of the refractometer but could not get room temp to 20C (68F) so I checked it at 72F and it was dead on. I did not have to change the calibration at all!

What now? Which one do I trust? Everything in the tank seems very healthy.

E

 

[SPC]

E, I don't think I am following you but I'll give it a shot. The difference between the reading at 68 and 72 should not make a difference. My question is when you say dead on what are you referring to?
Steve

 

[MedicineMan1]

I'd trust the refractometer, especially since it appears to be calibrated. I believe they are the "industry standard" when used in scientific experiments. But then again, I could be wrong...
To adjust your salinity, just use a weaker concentration of salt when you do your next water change or two.

[ September 19, 2001: Message edited by: MedicineMan ]

 

[esmithiii]

Steve,

When I went to calibrate the unit at 72F, it read 1.000 using RO/DI water right from the box. It did not need calibration.

MedicineMan:

Weaker water will not be enough. To go from 1.029 to 1.026 will take like 6 gallons of RO/DI water! All this in a 55! I plan on adding the 6 gallons (in addition to top off water) over the next few days.

E