You need more light. Do read the sticky threads in the lighting forum but the only one that addresses T8 is http://www.plantedtank.net/forums/li...t5-t12-pc.html
According to the second chart you are far below the amount that plants can do more than survive. How about getting a couple of the dome shaped work lights and some screw in compact fluorescent bulbs from a hardware store? That is easier than finding linear fluorescent fixtures less than 4' long and very inexpensive.
The plants will need food as well. Keeping it easy, just be sure to feed the fish for the nitrate and phosphate rich poop and get a bottle of aquatic plant food that contains potassium, iron and other micro nutrients and dose as directed.
Not sure the Myrio can survive low light situations. Don't worry about it, not fun but not all plants are going to suit every tank. There is a list of low light plants in the low tech forum, do look through and make a list of those that interest you in case you decide to buy more plants.