Calcium

[ggee1]

A question that we are not able to find the answer too! We have 150 gallon reef aquarium, 175 watt halide, 2 superblue 30 watt actinics, generally on from 9am to 6pm. We dose the tank with B-Ionics, but have noticed the calcium jump from 490ppm to over 900ppm. We have discontinued the B-Ionic dose for the past week and still see the jump in calcium????? We have also done 25% or more H2O change, which brings the level down to 490ppm but within 24hrs the calcium jumps again. We have also used two different test kits and the readings are the same. Any ideas???? :rollface:

[Randy Holmes-Farley]

That must be a testing error. Calcium cannot jump around like that. What brands of kits? Are you sure the units are ppm Ca++ and not ppm CaCO3 equivalents? How much B-ionic? What do you get for calcium in the artifical salt water itself?

[ggee1]

We checked it with both Seachem and Salifert Calcium testing kits. Both of those kits are measured in ppm. The tank is dosed daily with 50ml of B-Ionic 1 and 2.

[Randy Holmes-Farley]

It is not possible for the calcium to rise and fall between 490 and 900 ppm over the course of a couple of days without massive additions of calcium and alkalinity supplements, and when dropping, would necessarily lead to white precipitate all over the place. Are those things happening?

This calculator will show you how much you'd need to add for the calcium to rise that much:

http://home.comcast.net/~jdieck1/chem_calc3.html

In your case, that would take a full gallon of B-ionic.

[ggee1]

I see what you're saying there! I like that link, quite helpful! I checked the Alk this evening and found it has dropped to 6.4. As far as precipitates, there are none.... We had noticed some of the corals with very visible bleaching tips. Now this wasn't normal growth which led to the testing in the first place. Once we had done another H2O change (25%) we tested again and found that the Ca had dropped to around 800ppm... Again very strange!

[Randy Holmes-Farley]

I'd suggest checking with Habib in the Salifert forum. He'll walk you through the calcium test and make sure it is working right. :)

That said, if most readings are high and just an odd low one that is in error, the calcium certainly could be 800 ppm.