When and why is too high bad?

[bluwtr]

I have wondered this before but finally decided to ask. We all know that low parameters are bad on many reasons, but what does high parameters do? Obviously too high of pH is caustic; high temp cooks the critters and I've read that high Mg can kill inverts, but what is wrong with high Ca+ and Alk? I know that you get to a point and you are just wasting product and only so much can stay in solution and then it can precipitate out, but what about biologically?

Just wanting to start a conversation.

Wes

 

[Reefing Madness]

A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com