Originally Posted by ruby716
I don't have any live plants... you can go on the photo and video part of this site and see my fish and tank
First off, ruby716, I think this is the first thread of yours to which I have responded, so welcome to Tropical Fish Keeping.
Now to your light issue. I am assuming there are no live plants in this aquarium, in which case light is solely needed for your viewing pleasure. Fish do not need light, ordinary daylight in the room will suffice them, but viewing is nicer with a light. Restricting the light to your normal viewing time will solve this problem. It is, as someone suggested, preferable to have a timer so the light is consistent. Though this is of less significance without plants, still it is advisable. Fish like regularity too.
Algae is a plant, and like all plants it needs nutrients in the presence of light. Unlike higher plants, algae can use any light, even very little, to grow, and there will always be nutrients in a tank with fish. Live plants grab nutrients faster than algae can, provided they have adequate light to photosynthesize, which is why we say that having live plants can reduce or even prevent algae, at least from being troublesome. And "green water" is certainly troublesome.
Hope this helps your understanding of what's happening in that little eco-system.