I currently have a twenty gallon high freshwater community with a guppy, three danios, two corydoras, a nerite snail, and two platys. It has regular gravel as a substrate and currently only plastic plants. I was wondering if I could switch to live plants without changing the gravel? If so, what plants, and how many? What are the benefits and negatives to live plants and what care do they require? With the type of fish I currently have, How heavily/lightly planted should my tank be? Thanks.