46 gal question

46 gal w/40 watts+ambient sunlight = enough?

I have a cycled, stocked 46 gal with some plasticl plants and a few java ferns in the foreground. It has one 40w flourescent (came with setup from a lfs) over it. However, it gets lots of sunlight each day. It is against a wall and to its left is a sliding glass door; and to its right is a window. sunlight streams in all day pretty much in addition to the flourescent. In fact, during the day the sunlight actually washes out the flourescent (pic should show what I mean):


Also, this picture is old (doesn't show new deco and java fern) but hopefully you get the idea as far as the amount of sunlight it receives every day
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Does this kind of ambient light provide enough light to grow crypts, anubias, and other noob plants? I can't get more lighting right now regardless due to $$$ limitations, but thought I would ask before buying a bunch of plants if they are doomed anyways.

In fact, I do have algae problems. I have brown algae (which I gather from searching is diatoms?), and in between where the canopy meets the top of of the aquarium (hard to explain) i get this disgusting green algae. so far it has been restricted to the plastic so I just wipe it off once per week. As far as the brown algae goes I can't figure out whether it is from too much light or too little, I have read both on this site

thanks for the help. was going to go ferns/moss/crypt/anubias anyways since they are the hardest to kill