I have a 30 gallon planted discus tank. Both discus are doing extremely well. It is the plants I am having trouble with. They are staying green. They are just not growing. What am I doing wrong ? I have a new 5000K Flora Sun plant lamp that I run for 12 hours a day. I dose with Seachum products. ( flourish supplement, Flourish Nitrogen, Flourish Phosphorus & Flourish Prime, according to directions) I have a CO2 injector. I do biweekly water changes being careful not to siphon too deeply. ( just enough to get off the surface waste & not disturb the mulm that plants thrive on ) I use only sponges in my 2 box filters, alternating the sponges once a month & washing them in the waste water so as not to disturb the bacteria. My peramiters test well. What am I doing wrong ? Why are my plants not growing ?