How quickly will I see an effect after installation?

This will depend on a number of factors. If the boat is in the water and heavily polluted when the system is installed the algae and barnacles will begin to die off after only a few days. They will only be shrugged off by passage through the water. If the boat is regularly used then the hull should clean itself in a matter of a few weeks. Ideally though, you should start from a freshly prepared and clean hull for best results.