I've recenty completetly started over with my 20 gallon tank- I couldn't get it right- algae was crazy and I was loosing fish all the time, and almost all of the plants eventually died.
Through all of it, my 6 guppies have made it and so has a rock that has java fern growing off of it. The tank is now balanced and crystal clear. Where should I go from here? Right now I have a Penguin 100 w/ Biowheel filter, a heater, and that's it.
What else do I need to do/get before I introduce plants? I don't have a lot to spend on this, so I really need the most cost-effective way of doing this.
THANKS!! 
Through all of it, my 6 guppies have made it and so has a rock that has java fern growing off of it. The tank is now balanced and crystal clear. Where should I go from here? Right now I have a Penguin 100 w/ Biowheel filter, a heater, and that's it.
What else do I need to do/get before I introduce plants? I don't have a lot to spend on this, so I really need the most cost-effective way of doing this.