its a good amount of light. Im so mad though i have had this tank up and runnning for 4 months now but i have not added a single thing to it. The summer heat is just to much for the tank. Im running about 88-90. AC is not am option and a fan is way to much evap and it really only brings it down to about 85-86. Im gona wait till it getts a little colder out and them do something with it.