I know that this might be a little late in the post but anyways,
What would be really cool is for someone like a chemistry/Biology teacher to take and set up a new tank, (and I mean all new) and monitor ALL the chemicals in it (maybe daily for a while, monthly after it is really going then switch to a yearly thing). I know it would be time consuming, but it would be really neat to see. especially if it could be used to compare against other established tanks using other rules for water changes or in other enviornments.
anyways, just a thought, and it could possibly end some of the debate on these mystery chemicals. also i only used the example of teachers because i thought they would have access to the tools needed to run tests above and beyond what most of us alyeady do. I do realize there may be other jobs that would be in a position to do this type of thing.
let me know what you think
-=Cy