Hi! I tend to read a lot of posts without interacting, but this is such a great forum and I have a ton to learn, so I'll probably be more talkative in the future. I'm a longtime fish geek but am new to keeping plants (er, keeping healthy plants... I've had plenty of sad swords and cabomba over the years). I have a 4-month old 55 gallon that is evolving into a high-tech tank with simple plants (welcome back, sword plant! I'll do better this time). I've never used CO2 before and am trying to get a handle on the chemistry underlying KH/pH/CO2. I'm still getting over my intense fear of algae; I probably need more light and more CO2, but baby steps, right?