strange electrical problem

ok, i have a 50 gal tank set up with live rock and water (no fish or anything yet) i also have a rena cal heater which i have just discovered that it is leaking current into my water. I also have some blue moonlight LEDs which hang from the top of the tank and last night i turned them off before going to bed and noticed that one set of the lights was still on! even though they had been unplugged. thinking i was dreaming i got up to have a closer look and they were definitely lit up, not as bright but still glowing blue. I thought that it was some kind of energy build up at first? but they didn't go out and i also noticed that they were flickering on and off constantly. after watching them for a while i started thinking about stray currents found in the home aquarium and noticed that part of the wire leading up to the first set of lights was touching the water, so i turned the pump off which was causing the water surface to calm and the lights stopped flickering. Then the light on my heater came back on (rena cal heaters arent on constantly) and the blue lights went out. So this means that the current going to the heater was actually going to where it was supposed to.. and when the heater temporarily goes off the current is going straight into the water for some reason. Does anyone have any thoughts on this? Is this a problem with where the electricity enters the heater via the wire at the top and not the tube? also i cant afford a new heater until next week is this a potential hazard for the time being? i dont intend on putting my hands in the water by any means but would like to keep my live rock alive until i get a new one..
thinking about the lights this probably also means that the wire is faulty also so a bit gutted about the equipment..

one last question, the heater i have now, i am very happy with so will probably buy the same model. But also want to invest in a circuit interrupter ( one of those specially made for aquarium use) will the continuos switching on and off of the heater affect the GFCI at all? not 100% sure how the heater works, all i know is that it heats up and then shuts off until the temp starts to fall again..

any help will be greatly appreciated

 

As far as the moonlights are concerned I know that they will continue to glow and flicker even after they are unplugged for some time because they continue to draw power that was stored in their transformer. Since led's take next to nothing to run on, they can glow for quiet a while even if you unplug them. As far as the heater is concerned, it should not really be a problem. You can even remove it if you are worried about it depending on when you are going to get your next one with little or no die off on the rock. However, I would obviously invest in a new heater if you are worried about it as well as a grounding probe to ensure that when you do add fish and or coral that something like this does not come up again and shock the heck out of your live stock. Cool thing about these is for about $15, you will not ever have to worry about shocking your livestock ever. It is a good preventative measure IMO. Check out the link to see some probes. As for the exposed wire on the lights, pick up some stuff that is called liquid tape or liquid electrical tape in the electrical section of homedepot, walmart, or somewhere like that. Slap some of that on the exposed wire and you are good to go.
grounding probe | Marine Depot