Afterward, I change the configuration to a large "Âo±í" (~200G/Hr) and no sands at all. I can then keep 2 x 6" ÂÅ¥Û¯Z for over 18 months.
So, 24" Tank should be okay for the small fishes ... as far as U can maintain a good water condition. I am now having a 36" Tank ... and still keeping 6 x 6" ÂÅ¥Û¯Z ...