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View Full Version : does adding calcium raise salinity


ruggirello2
02/08/2010, 04:44 PM
I realized my salinity was at 300 ppm so I have beed dosing Kent's Turbo Calcium. Every time I dose my salinity raises from 1.026 to 1.028. That is in a 220 gallon system, I am only dosing 5tsp. of calcium.

Randy Holmes-Farley
02/08/2010, 05:10 PM
It is not rising that much. It rises a very small amount due to the calcium and chloride ions you are adding in that additive. Boosting calcium by 100 ppm with that additive will boost salinity by about 0.3 ppt, from, say, 35 ppt to 35.3 ppt. That is similar to a sg of 1.0250 to 1.0252.

How are you measuring salinity?

ruggirello2
02/08/2010, 07:33 PM
with a marine depot refractometer. It is seriously raising from sg 1.026 to 1.028 just by raising the calcium by 12.5 ppm in a 220 gallon system. Could it be my auto top off is malfunctioning?

bertoni
02/08/2010, 07:43 PM
I'd guess that the autotopoff is having a problem, or that the SG device is causing problems. It'd take a huge amount of calcium to make that change in the SG.

ruggirello2
02/08/2010, 07:49 PM
what about magnesium, does mag. raise salinity, something is up, I just checked the salinity and it is almost 1.030 sg and this morning it was 1.026

ruggirello2
02/08/2010, 07:55 PM
I forgot to add that my auto top off does work. The salinity wasn't rising before I started bringing my mag and ca up. I am dosing tech m magnesium, I am raising my magnesium 110 ppm a day, is that safe?

graveyardworm
02/08/2010, 08:07 PM
So when you dose 5 tsp Ca the salinity goes from 1.026 to 1.028? That does not include the Mg? Dosing Mg will also have an effect on SG if you're dosing more than the tank is using on a daily basis. 110 ppm is quite a bit per day, but as I recall I've probably done that much or even more daily to raise mine and not had a problem. At that rate though you definately have to keep an eye on your salinity and adjust as necessary.

bertoni
02/08/2010, 09:24 PM
110 ppm of magnesium likely is safe. I wouldn't worry about that. Dosing magnesium will raise salinity to about the same extent as calcium. Something else is going on.

ruggirello2
02/08/2010, 10:57 PM
I'll see what happens once I am done dosing mg and ca, meaning I'll see if my salinity still rises.

Chris27
02/09/2010, 08:23 AM
Just a sanity check, but you wouldn't by chance be using SW in your top off would you? I unknowingly made that mistake when I first started a few years ago...

ruggirello2
02/09/2010, 07:38 PM
no I am not using salt water in my top off