Hey, yesterday i did a water change with a new gravel/water changer thing and its battery operated. It told me how to clean the gravel, but i dont have any gravel, only live sand. The water dumped out fine, but some sand got sucked into my dirty water bucket. The end of the gravel vac had little slits for gravel, but not sand. i got some of the sand clean and everything looks good today. I was just wondering if there was a differ gravel vac i could use for a marine aquarium with sand.