I wanted to start a discussion regarding tanks that have a lot of
light, at least 3-4 watts per gallon (wgp). I have two such tanks and
have had a lot of problems. What are other people's experiences with

You should give more information to really start a discussion. You have just
given one parameter that is light. What kind of a problem you are facing? If
its algae what kind and what are NO3, P and other nutrient levels.

Dominic