Why is my calcium so high?!?

[talon4x4]

Decided to do some testing today and my calcium is thru the roof. I'm getting a reading of 700 with a Salifert kit. This is how I arrived at a reading of 700, not sure if its the correct way of doing it or not. I filled the syringe once with the CA-3 fluid, used all the fluid (no color change), filled again and stopped at a reading of .60, which = 200 (color changed). Added the 500 and the 200 to come up with 700. I did this twice and came up with the same number. Next I tested a batch of Reef Crystals I have made up for a water change. The water came up as 400, tested twice to make sure. The only thing I dose is the BRS alkalinity solution (soda ash) and BRS magnesium solution (Magnesium Chloride and Magnesium Sulfate mix). I also only topoff with lime water.

My current parameters:
dKH = 8.0
pH = 8.31
Temp = 81.1
Salinity = 1.025
Mg = 1500

Any thoughts??

[bertoni]

That method of measuring is perfect. :) I would stop dosing the alkalinity part for now, and check that there wasn't a mixing error for the calcium solution. Making a very strong calcium solution is very easy: it's the alkalinity part that limits concentration. You could try adding some of the supplement to a 5g container of water, and see whether the results are in line with the calculator:

http://reef.diesyst.com/chemcalc/chemcalc.html

[talon4x4]

Problem is, I haven't used any of the calcium solution. I don't dose anything to boost CA. My Ca has slowly risen to this level over a couple months without any Ca dosing. A couple months ago I was running around 450. I tested periodically and it was rising, 500 then 600. Now its been about 1 month since testing and I'm at 700.

[bertoni]

Wow, that's very strange. What's been going into the tank? Is there any artificial live rock in it?

I saw that you're dosing:
limewater
alkalinity solution
magnesium solution

Is that it?

[talon4x4]

All live rock and sand, nothing artificial. Yes, those are the only additives going into the tank. The only other thing going into the tank is food (frozen, flake or pellets).

[bertoni]

Well, I might check whether some of the solutions have been switched. Maybe you're dosing calcium instead of the magnesium. That's about all I can imagine that could cause this.