How do you keep your substrate from being drug into the water dishes all the time? Does anyone have a substrate change around the water bowls? I have EE and was thinking of getting some aquarium gravel to lay around the water dishes so some of the EE would fall off before my crabs took a swim. They also seem to push the EE up close to the water dishes and it then absorbs all the water from the bowl. If anyone has any pics can you please share. I need to go buy crab food today and thought I would get a bag of gravel while I'm shoppin. thanks!