First, are you saying your tank had no light at all?
I have tanks near windows, and I still put a light over them. A flourescent tube should be fine, in addition to whatever natural light you are describing. Buy a timer (they're cheap) and set the light to be on for 10-12 hours a day.
You will also need a liquid fertiliser, and from what I hear, flourish comprehensive is the best.(I use soil, but flourish is decidedly easier)
For plants, I'd try swords (Echinodorus blehiri, or klienar prinz, or rosette sword), vals, Java Fern
, Java Moss
, and Anubias
May also want to add Duckweed
or azolla. The Goldfish
will probably eat it, but better they eat that than your other plants. Duckweed
grows super fast, I bet they couldn't ever get it all.
For a longer list, track down Lupin on this forum. He's the Goldfish
plant expert. :)