That tiny little tingling sensation in the cut on your finger, which is caused by stray voltage in your aquarium, may not seem like much to be concerned about, but in reality it can cause constant issues. The voltage is coming from one or more pieces of equipment, which may not even be submereged. The electricity is constantly pulsing through your aquarium, and it can cause all sorts of problems with fish, coral, and invertebrate health. Most of it goes ignored or unnoticed without any repercussions, but you really want to take care of it as soon as possible to avoid any long term effects. So, unplug all of your equpiment, and we mean all of it. Then, plug in items one by one until the culprit is found. It can be water pumps, light fixtures, heaters, you name it. Just find out what it is and replace that item.