Join Date: Nov 2007
Location: NYC & Long Island, NY
Okay, a couple things. First off, if you're going to go with an airstone, Id chose a limewood airstone. I'm using a glass nano diffuser off ebay, and I find that it clogs a lot less than the airstones I was using before, which I was generally unhappy with.
I think a DIY system is fine for a 7 gallon tank. Just keep up on your DIY solution so that you dont have fluctations in your CO2 levels... algae can get a foothold if you don't realize your CO2 output has tapered off.
Flourish will definitely help, but keep in mind that this adds only micro nutrients to your tank, not the macros that are pivotal to plant growth. You'll need a source of Nitrates, Potassium, and Phosphates. Some of that will come from the fish food you add to the tank, but you may find that you'll need to supplement them as well.