Oh wow, where to begin, lol.
I've grown these plants in 20 or smaller, under various types of light, and I don't use fertilizers. I am a strong believer in the "natural aquarium" and mine thrive.
(broadleaf and narrowleaf) Java Fern Java Moss Anubias
(Barteri tend to get huge leaves... the smallest species is nana)
Compacta sword (dwarf species of sword plant) Hornwort
Elodea (another common name is Anacharis
(I trim mine from the bottom instead of the top as most do)
Crypt lutens species
Micro sword (not for the beginner)
Dwarf sagitaria (grows just tall enough to make a good background plant, can be trimmed at the top if it gets too long)
Plants I stay away from in small tanks:
other than nana
Needle Sagitaria (gets way too tall)
All of the val plants (get way too long and shed alot, which pollutes water quality fast)
Aponogetan any species (grows way too large)
I can probably keep the list going once I sit and give more though to the many many tanks I have kept over the years. The thing to remember is that any plant will require trimming to some extent if it does well in a small tank. Some grow tall, some grow wide (like Anubias
), and some grow in every direction. Just like with fish, you should always know what it is before bringing it home, and have some understanding of what it needs. Some plants require low light, some high, some prefer cooler temps, some warmer, some require extra fertilizers such as iron to keep their color good (especially the plants with red tones in them), some do fine without fertilizers. Every plant has special needs, and knowing them is 1/2 the battle. There are some good books, and if anyone here is interested, I can look up some titles/authors for you, simply let me know. One website I've found to be pretty accurate and offer a lot of information on plants is http://azgardens.com
One other note... always check to see if the plant you've chosen is amphibias or fully aquatic. There are often plants found at LFS's that are amphibias in nature, and once submerged, don't do well, and over time die out for no reason. There is a reason... most LFS's don't know 1 plant from another, making it your own responsibility to know what you're spending your money on.