| | Re: 55g THIRD TIME! ;)
Plants need a carbon source but they also need NPK and trace elements. You can still use the excel, at recommended dosage, not straight at the plant. BUT you need to also give them the macro (NPK) and micro (trace elements) fertilizers. You can use dry ferts. Dry ferts are available at Greenleafaquariums.com
Or Seachem makes a line of liquid ferts. They sell Flourish trace, Flourish Nitrogen, Flourish Phosphates, and Flourish Potassium in separate bottles.