水草情迷

after looking tcc's new tank for small moon moon, i am very jealous of his short pearl grass. one 11 w PL tube with 'jit jit' co2 and they still grow very healthy. but, mine.......... up to 4 inches high now!! they are tall pearl grass now!! all of them are individuals, they never grow new stem, never grow horizontally, only up up up up...........
i use diy co2, 'jit jit' co2, one 27w PL tube and one 10w FL tube [has changed to a 10w blue tube now]
dupla plant 24, 1 drop for every week, ph is lower than 6