alkalinity high what should i do

[jeffbrig]

I wouldn't add Ca to encourage precipitation.

First off, see if you can verify your measurement with a different test kit. You may not be as high as you think. Even if you are, alkalinity should fall pretty quickly as it's used up by things in the tank (my system consumes about 1dKH per day). If nothing is showing adverse affects, I'd be tempted to just stop dosing and wait it out for a few days. If you start to see any problems, be ready with the water changes.

I've heard of people running tanks as high as 12-14dKH to combat algae, but I typically target 10-11 in my own system.