There are water quality tests and water chemistry tests.
Water Quality:
While a tank is cycling and rock is curing, you will need ammonia, nitrite and nitrate kits.
After a tank has cycled and the rock is cured, you would probably need to monitor nitrate and phosphate. Testing for ammonia or nitrite would be useful if something seems out of whack, if something dies, or something like that. I usually use less expensive Aquarium Pharmaceutical test kits for water quality.
Water Chemistry:
Alkalinity, calcium and magnesium tests should be done every month at the very least, imo. I use Salifert test kits for determining water chemistry.
Checking salinity and pH are also important. The most accurate way to test salinity is by using a refractometer. The swing arm salinity meters are sometimes quite inaccurate. The best way to test pH is to use a probe and digital readout thing (don't know what it's called
). These two items are a little on the expensive side, but well worth having in your reef testing arsenal.
Here are some reef chemistry calculators and articles that will help you better understand alk, Ca and Mg in a home reef environment:
Aquarium System Volume Calculator:
http://home.comcast.net/~jdieck1/volcalc.html
The Reef Chemistry Calculator:
http://home.comcast.net/~jdieck1/chem_calc3.html
What is Alkalinity?
http://advancedaquarist.com/issues/f.../chemistry.htm
Calcium:
http://advancedaquarist.com/issues/mar2002/chem.htm
Magnesium in Reef Aquaria:
http://www.advancedaquarist.com/issues/oct2003/chem.htm
How to Select a Calcium and Alkalinity Supplementation Scheme:
http://www.advancedaquarist.com/issues/feb2003/chem.htm
The Relationship Between Alkalinity and pH:
http://www.advancedaquarist.com/issues/may2002/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
HTH
