Oh boy...[b said:Quote[/b] (Tamlin Dawnstar @ Sep. 05 2004,1:27)]Spec,
If you rinse your potting materials before you use it to pot, then run the water through it, it should be below 100 PPM, and that is the whole point.
I repot when there is moss too. It is a good protocol. Even with taking care to keep things clean, I still get moss and algae from time to time. If it gets to the point where I can't fix it by top watering and leeching out the salts, I transplant immediately.