Well, initially, the lights were on for about 12 hours, and I think that was too much. Now they are on for about 7 hours, honestly. We used to put them on when we woke up...around 6:30am, and then off when I got home, again, around 6:30pm. I read that was too much time, 12 hours, and some plants looked unhappy, bit brown. So then we tried putting the lights on when my fiance leaves 1pm and then off after I get home, around 7pm. So what is a good amount of time you think? Eight hours? From like... 1-9pm. If we turn them on when we get up, it's just TOO many hours until I get home.
As for it being medium light, they seem happy, the ones we have. Some were from an original order of (low lights) before we got the better bulbs. They still seem ok.
CO2 ampules are just little plastic bottles of liquid CO2 that you put in the tank, they release over 2 days, last for about 20 days. You watch pH and the plants to see how they do. They get greener and we have a lot of new growth.
As for fertilization, not yet. We were told to take it slow, see how they do with lights, CO2, let the fish get used to the CO2, which shouldn't affect them, etc. And the Eco Complete substrate apparently has all the goodies in it, carbon, iron, etc. It has good bacteria and comes packed wet. You drain the bag and put the substrate in your tank. It naturally creates layers. So that's what we've been doing so far...
The one time I put "plant food" in for the plants, aquarium plant food that is, the tank got cloudy out of nowhere and it freaked me out. I did a water change and it was fine that afternoon. Our tanks are all clear and have barely any smell, etc. So I get nervous when something weird happens like that. So I have stayed away from fertilizing anything
One person at our pet store did suggest a plant supplement, liquid additive, but b/c we have substrate, he said to see how it goes first...
So far, the worst thing that's happened is the Mollies and their appetite for plants. They seemed to have eaten what they liked and left everything else. So we removed the eaten/decaying plants and reconfigured everything with some beautiful rocks.