Water Chemistry Question

yes its caused from fish waste but also decaying fish food (uneaten food)

ph is basically how acidic ur water is. the more acidic the the lower the ph.

i dont know exactly what makes up alkalinity and hardness, i just know how to adjust them. alkalinity refers to ur waters ability to maintain a certain ph.

hopefully somebody else can fill in the blanks

alkalinity as we measure it with test kits is carbonate hardness, This buffers the tank against pH crashes, and is typically consumed (Slowly albiet) by natural processes in our tanks

GH as we test it in the hobby is usually a measure of MAgnesium and calcium Ions specifically, some test kits will read the total of CaCo3 to give you your GH reading.

Honestly the numbers you are reporting would tend to make me believe you are using dip strips, or have a bad test kit or two.

If It's dip strips, The best way to use them is an ignitor for the grill or fireplace, they aren't consistant at doing anything else well.

If liquid tests, then I'd take some water to the LFS and have them verify your results.

In the articles forum is a great write up by Happychem on basic water chemistry

right. it's very difficult for aquatic life to affect hardness, unless it is either depleting minerals (which contribute to GH, General Hardness) and carbonate (responsible for KH, carbonate hardness) or adding them by shells dissolving. Acidity (lower pH) can be experienced in very dirty water. The buildup of wastes contributes to acidity, but I don't remember how exactly.

here is the link to an article on water chemistry for beginners http://www.aquariacentral.com/forums/showthread.php?t=75895
Contained in that article, is the link to the hard-core water chemistry article by happychem. It's pretty overwhelming if one is not trained in science.