Could you recommend some fast-growing plants that will do well in a
relatively low-light environment but that will still take advantage of a
rich substrate? I've got a flourite-substrate tank with about 30 watts of
light on a 20 gallon long tank (which isnt that little considering the
plants are less than 10" from the light). I need some short plants that
will be fairly hardy in most water conditions but that will be able to grow
fast enough to help me with algae. I was hoping someone might be able to
recommend some easily obtainable plants that would do well in these
conditions.

Hygrophila grows very fast, and needs only moderate light. It may even creep
along the substrate rather than grow vertically, if there's a lot of light.
Even if it does grow vertically, it's easy to prune. You can just cut the tops
off -- no need to replant. It will grow back twice as thick. Hygrophila
difformis is especially pretty.

Vallisneria would probably do well in a tank like yours. It takes awhile to
get established, but once its established a root system, it grows like crazy.
Corkscrew Val usually stays under 12", so might be a good choice for your tank.


Swordplants would do fine with that substrate and that lighting level. They
get rather large for a 20 gallon tank, but it takes awhile. And there are also
smaller swordplants. Pygmy chain sword, rosette sword, etc.

Sagittaria subulata is one of my favorites for a moderate-light tank. Like
Val, it takes awhile to get established, but once it does, it grows very fast.


Also consider java fern. It doesn't need much light or a special substrate,
but will grow very fast if conditions are right -- fast enough to help in the
algae wars.

Marsilea might make a good foreground plant for you. It's not commonly found
in pet stores, unfortunately. I got mine from FloridaDriftwood.com. It's a
pretty plant, that makes a good ground cover when grown submersed, and doesn't
need as much light as most "lawn" plants. Mine is growing pretty well in
fairly deep shade. Looks like little clovers.

Speaking of FloridaDriftwood, they apparently are carrying "algae balls" now --
Cladophora. These do well in low-light tanks with no CO2 or anything. They
don't grow fast, but they are pretty cool-looking. I might buy some, for my
low-tech tank.


Leigh

http://www.fortunecity.com/lavender/halloween/881/