yes another light question

This question is purley about esthetics. When the sun is out my living room is bright and I see the fish, but on rainy cloudy days like the last few the tank is to dark to see in. We are always home and love to watch the tank in passing during the day. I now have the timer on from 2pm till 10pm and things seem to grow well. I just would like to see my tank more but it does not have to be real bright. How do tanks in aquariums or resterants get by with the main tank lights on all day? I don't ever want algae like others with to much light. Any idea's

 

I think I will try to cover up half the light to see what happens and remove it at night to see the fish even better. With the light so strong I bet I may have to keep it covered almost all the time. but maybe if it is half for say 5hrs and full for 9hrs it might work. As you know down there we also get a lot of winter light so it isn't always dark and gloomy.