Water - what to test for and how to make things right

Here's my question. In the process of setting up a new tank (55 gallon with 20g sump fyi) and I need to know what to test for in my saltwater. Obviously you need to test temperature, salinity, ammonia?, nitrites, and nitrates. What else do you need to test for and why? pH?

And then when you're testing and some level is out of whack, how do you fix it?

Sure temp is fixed with a heater/chiller, salinity is fixed with salt or water, ammonia, nitrite, and nitrate are fixed with your biological filtration and water changes. But how do you raise or lower something like pH? Or alkalinity? I'm not even sure what the heck alkalinity does or why you need to test for it...

Help pretty please ;D

 

LOL, a guy I work with survived a helicopter crash and his nickname was CTD - Crash Test Dummy - for a while after that.

Ok, if it's fish only, then test Alk, ph, salinity, nitrates, phosphates, (and nitrites and ammonia for when you first cycle your tank).
If you are making it a reef tank (coral), you'll also need to test Calcium, Alk, and Magnesium primarily.

Lots of good info reading through the "chemistry" section of this forum.
http://www.3reef.com/forums/water-chemistry/
Welcome to 3Reef, by the way.

 

pH is the amount of acids and bases in the water. Typically tanks tend to run a lower pH with time as the acids from fish and invert wastes build up. Using kalkwasser or BAKED baking soda will raise it but the kalk is going to be FAR more effective. kH is the alkalinity, which in simple terms is the amount of carbonates in the water, with bicarbonate being dominate. Alk does many things but mainly buffering the water-helping prevent the acids from lowering pH, and is used by corals and fish to make bone, like seen in corals as CaCO3. If alk is high, it usually stems from using tap water, which you can solve by using RO water, also if its caused by supplementation just cease the supplementing and perhaps do a water change to lower it if you feel its really out of whack. You can raise kH in many ways, kalkwasser, baking soda, buffer supplements and so on.

Good luck and keep testing!!