I have the same problem with my amazon sword. My light is 15 watt in 20
gallon about same as yours. I have tried the root tables, jobes sticks and
seachem flourish fert and they dont seem to help the swords much. I also
have DIY CO2 running and do water change every 10 days.
Other plants ,java fern and anubius are doing great. My next option is to
increase the lighting to 30 watt. Hopefully this is what the sword needs. I
also had rotala indica in tank and it has slowly died.

I'm fairly sure your problem is insufficient light. Amazon swords don't need
killer amounts of light, but they do need more than java fern and anubias. The
fact that the low-light plants are doing well, the medium-light Amazon sword is
suffering, and the light-loving Rotala died tells me light is the problem in
your tank.

30 watts over a 15 gallon tank should be enough for an Amazon sword, and it's
not so much that you need to add CO2.

Of course, then you'll run into another problem: a healthy Amazon sword gets
*way* to big for a 15 gallon tank. :-)




Leigh

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