Im have alk problems.

[Beverly]

Somebody mentioned posting reef chemistry articles

Sean,

Water changes will not keep calcium levels up, unless you are dripping kalk, and maybe not even then. It depends on the calcium uptake in your particular tank. Also to be considered in the grand scheme of reef chemistry is magnesium. Mg, along with Ca and alk, needs to be tested and corrected at least every other week.

But back to your low alk and high pH. Baking soda will raise alk but lower pH. I've got two tanks that have consistently high pH and sort of normal alk due to dripping kalk. To reduce the pH of the kalk, I add some vinegar to the kalk/RO mix so the pH doesn't rise when I drip kalk.

Anyway, about those reef chemistry links...... the list just gets longer

Aquarium System Volume Calculator:

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

The Reef Chemistry Calculator:

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

Reef Aquarium Water Parameters:

http://reefkeeping.com/issues/2004-05/rhf/index.htm

Magnesium in Reef Aquaria:

http://www.advancedaquarist.com/issues/oct2003/chem.htm

Solving Calcium and Alkalinity Problems:

http://www.advancedaquarist.com/issues/nov2002/chem.htm

High pH: Causes and Cures:

http://reefkeeping.com/issues/2005-03/rhf/index.htm

Low pH: Causes and Cures:

http://www.reefkeeping.com/issues/2004-09/rhf/index.htm

Whew! Posting them is the easy part. Reading and understanding any of it is where the blood and sweat come in