Some more of mine. These are older and, unfortunately, just like a chemical, they apparently are degrading with time. Equations and symbols seem to be having problems, so some are becoming harder to read and understand:
(links updated March 31, 2004)
The Complete Nitrogen Cycle
http://web.archive.org/web/200305101...&RecordNo=3090
Magnesium (older article with fonts screwed up)
http://www.aquariumfish.com/aquarium....aspx?aid=2345
Phosphate (older article now reproduced in a poor fashion)
http://www.aquariumfish.com/aquarium....aspx?aid=2276
Carbon Dioxide
http://web.archive.org/web/200305041...&RecordNo=2074
Using Conductivity to Measure Salinity
http://www.aquariumfish.com/aquarium....aspx?aid=1804
Understanding Seawater
http://web.archive.org/web/200306202.../1/default.asp
Protein Skimming: How It Works
http://web.archive.org/web/200103090...skimmers2.html