Hi, I just got my first aqarium, it's a 5 gal tank has a filter and a heater, and it has 6 watts of light. I have a banana plant, Anubis and a moss ball. I have been using flourish, and so far they are doing well. I would like to maintain a low-tech as possible tank, no co. I might add some frog bit eventually but that's it. The fertilizing thing is confusing to me, can I just use flourish, or do I need iron and other stuff. What's the bare minimum, for just a few plants? I should mention to that our town has well water which is very hard water.