DO NOT,i repeat DO NOT get the Carib-Sea sand,it's synthetic,and too light.......it gets waterborne quick and grinds in beetween your impellar motor wall......which makes it stop working.The black Tahitian Monn sand is just heavy enough to stay down.....also big Plecos will burrow sending LARGE clouds of sand into said impellar......the white quartz(pool filter sand) is THE best sand to use..........
