You can start seeds under 40W (or 45W) but not very many. About as many as would fit directly under the tubes, not much more than a square foot.

Things you might grow from seed such as annuals or vegetables typically require quite intense light or they stretch. You might be better off starting them on your window where they would get direct sunlight.

African violets and most things grown as houseplants don't require such intense light and you could grow several of them under your lights. You could probably fill the aquarium with low light plants such as some ferns, the african violets, etc.

I grow all the plants for my vegetable garden that need to be started early under lights. I went to my local hardware store and bought two four foot double bulb hanging shop lights(retail $8.00 each), and the four forty watt bulbs that go in them(about $2-3 for two bulbs). None of that fancy expensive stuff. As soon as my plants germinate, I drop the lights right down on them so that they don't get leggy. And they won't get hurt by touching the cheap bulbs, as they don't get hot. When the plants start running into the lights good then raise them up an inch. When they're big enough, harden them off and plant.

Thank you both. I will leave my 45 watt setup alone, as I have no more room to put lights, and keep my 2 African Violets and my brake fern in there. I also have a 20 gal set up with 2 20 Watt fixtures - to this, I will add another two 20 watt florescents for a total of 80 watts. I really had no idea what the wattage requirements were for this sort of growing, so I appreciate your replies. I am thinking of growing some citrus seeds, hope it works out! If anyone has time for a quick answer, I'd love to know if 80 watts are enough to grow from seed, and how far from the light they should be. I think I will opt for bbinion's plan and keep them right near the light. Thanks again.

Eileen