Hi, I have a 55 gal tank. I do 50% water changes weekly.I inject co2, fert three times a week. Lights are two 96w cf lamps one is 1,000k the other is 5,600k also have four screw in cf bulbs 5,600k a total of 240watts.nitrate is 15 ph 6.6 kh4 dh5 . I have lights on for 8 hrs, co2 also. Ricca doing great,amizon doing great,bunch plants not lasting.green weindet getting black and getting holes in the leaves.Co 2 checker is on the light lellow side. Riccia not pearling. WHAT AM I DOING WRONG and how can I correct it. Thanks Ed