i just transferred all my plants from a 29g to a 55 gal. anyways, some of the leaves on my cryptocoryne lutea are starting to turn yellow and the stems are melting. everything else is pearling and growing great. i have schultz aquatic plant soil mixed with gravel as a substrate. i use flourish tabs, flourish liquid, and leaf zone fertilizer. i have 2 two lamp shoplights using` 2 ge chroma 50s and 2 6700k ge daylight bulbs for a total of 160 watts. ph 7.2-7.4, kh 4-5. diy co2.