you can try using flourish excell or diy co2 but from experience i would say you have too many nutrients. so i would try to cut this back.
to cut it back you need to look at your fish load(how many and is it over stocked), how much your feeding (is it possibleyour over feeding?) and mantainence (are you gravel vacumming out the stuff)
One you sort that then you can have a go at playing with excel/co2 and ferts to get good growth on your plants