I have a 55 gallon aquarium with several amazon swords, some Ludwigia , Bacopa, and java fern that are potted in Flourite except for the fern. They have been in the aquarium for about 2 months and show little if any growth several are slowing giving up. I have approximately 2.9wpg 10hrs., do 30% water changes weekly and have fertilized with jobes sticks. I added some Elodea as a water quality indicator, it is even growing poorly. I have tested it and it seems ok. I have about 20 convicts and 6 small botia. Does it need a CO2 boost?