We have 2 Fluval Edge 6g that my daughter got. I kept the light, use liquid carbon daily, and ferts once a week after WC
's. I have ambulia, dwarf chain sword, crypts, bolbitus, java fern wendilov, and anubia's growing in them and they actually do quite well. But I do believe the liquid carbon is the key for the good growth I get using that lighting as the ambulia shouldn't be able to grow in that light.