High Cal./Normal Alk?

[xabo]

I have a 210 gal. tank w/a 40 gal. sump. Just tested water params., and - Cal.= 600, Alk= 3.45 meg using Salifert kits. PH=8.15, Temp.=78.5. I'm using Oceanic salt, and a Geo CR w/ Koralith media. I know that this salt has a high level of cal. How can I get the numbers in balance? TIA.

[Randy Holmes-Farley]

The values are OK as is, as the drawback to elevated calcium is low alkalinity, (and your alk is OK).

But if you want to bring the calcium down over time, add an alkalinity supplement such as baking soda each day. That will slowly reduce the calcium level relative to the alkalinity. I'd bake the baking soda at 300 deg F for an hour to give it a pH raising effect since your reactor probably drives the pH down.

This article should help:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

[xabo]

Thanks for the reply. I'm mixing saltwater for a water change now. How much of the Baking Soda solution should I add? (I already have it mixed) Should I shut down the reactor?

[Randy Holmes-Farley]

I'd suggest adding about 4 teaspoons per day (in a 210 gallon tank), dissolved in some fresh water.

I'd leave the reactor running.

If you get too much white precipitate on things, add the baking soda more slowly.