Which would you believe?
 

Hi,

I have just brought a Refractometer and have got a reading of 1.030sg!! Quite surprising considering my usual Hydrometer shows 1.025.....

We always rinse our Hydrometer with fresh water and it's only 4 months old? Never thought they could be this far apart?

Any thoughts? :idea:

Regards, Simon......

If the refractometer is calibrated, I'd believe it.

Yup, calibrated refractometer is right. what are your Ca levels like? My water was 1.30 and Ca was over 500

yep as long as you calibrated it the refractometer is right

Hi,

Ca was 460ppm yesterday, dKH was 8 & MG 1400ppm, I haven't noticed any problems with the tank... Does any one else keep their salinity this high? :question:

I have checked the Calibration & all seems fine....

Just thrown the Hydrometer in the garbage.... :rip:

460 is on the high side, unless your using a lot of additional Ca, that might be from the salinity being too high. 1.030 is too high, but the easiest thing to do is take a sample to the LFS or a buddy with a tank and check it a third time.

You should lower your salinity to 1.024-1.026. Do it very slowly.
What brand of salt mix you use? If you lower your salinity the ca level will drop accordingly.
I recommend you check these parameters on weekly base:
Salinity, ca, alk, mg, po4, no3. Keep it on excel chart so you can identify if your system develop some tendency to go to the wrong direction.

I've compared several hydrometers with my refractometer and I've seen some that were out as much as 0.006.

I also use a sample of known salinity to calibrate my refractometer yearly http://www.jlaquatics.com/product/pp...+Solution.html so I feel confident that I'm getting accurate results.

Hi,

I use Reef Crystals, My SPS at the moment consume my Ca fairly rapidly
I had been looking to maintain salinity at around 35ppt or SG at 1.025 / 80f degrees.. All other parameters are great .

Thanks for the reply.

S