Are Pods able to swim through the water? Because I have some sort of "pod looking" organism in my tank. The other day while moving a rock, it darted out, but it was so fast and little it was hard to follow where it went. I do have other pods, that are really small, but it doesn't seem like they are able to swim, they get caught in the currents all the time and don't seem as if they can fight it, just settle where the current takes them.