Calcium high, pH LOW, alk ok NEED SOME HELP!

[whalloper]

another day, another problem...

my top-off system decided to go nuts and dump all of the water (thankfully only about 4 gals) into my sump. My top-off water contains Seachem Reef Complete (with magnesium and strontium).

Needless to say, my calcium is above 500ppm. My pH has dropped to 7.8 (yikes) but my alk is ok at 9dkh (typical). Salinity is lower than normal from all the fresh water, but not much. So, does this make sense? I would have thought my alk would have dropped to cause the pH drop - am I wrong?

So to sum up params:

Calcium 500ppm+
Alk 9dkh
pH 7.8
Salinity 1.025
Nitrates 0
Phosphates 0

I dont test magnesium and strontium, could excess of these lower pH???


Is there anything I can do?

[Randy Holmes-Farley]

I dont test magnesium and strontium, could excess of these lower pH???

No,and I doubt they rose much anyway.

I'd just keep maintaining the alkalinity with baked baking soda and let the calcium come down on its own. Also, I'd get a true reading for it by adding a second syringe of titrant and add the values together. That way you can track its decline.

[whalloper]

so does baking the baking soda raise pH more than not baking it?

[bertoni]

Yes, baking the baking soda converts it to sodium carbonate, which is a higher-pH supplement. This article talks about why that that's true:

http://www.advancedaquarist.com/issues/april2004/chem.htm

For us chemistry illiterates, the baking drives off CO2 from the baking soda, which leads to a higher pH, since CO2 form carbonic acid when dissolved in water.