Hello everyone. I have a pretty big tank for a beginner and have not much previous experience in the field. I have 48 X18 inches rtank with 30 inches height. Freshwater non-plantdd acquarium with Marina CF 40 external filter. I have used Lava Sand at least that my petstore manager call it and as per his advice it is good for controlling ph level and warer clearity. However I do not find any literature on this. I am wondering that he fooled me on this. Initially my water was cloudy and muddy however it is cleared in last one month time. But whenever my clown loaches and chinese algae eaters dig in lava sand, it becomes dirty. What should I do? Cover sand with gravel layer? Replace lava sand with other sand? Please suggest.