I have a 55 gallon tank that currently has plastic plants in it. I've been thinking about switching to live plants for a while, but haven't really done too much research on the subject. For substrate in my tank, I just have regular aquarium rocks that you buy in a bag at Walmart. I guess they're more like pebbles, not the really tiny colored rocks you can buy. If I go with live plants, am I going to have to replace my substrate, or are there any type of plants that can grow in what I have? Or is it possible just to plant them in little pots or whatever, and then cover the pots with rocks? As far as lighting goes, I just have the two single lamps that came with the kit when I got it. I'm not really sure what wattage they are or anything, the bulb just says "Eclipse Natural Daylight" or something like that. I can get better bulbs, that's not a problem. I really don't want to have to buy a CO2 unit, either. So is it going to be possible to have live plants in my tank or not?