lanny,
voltage exhists in most everything and most everywhere.. that does not mean it is all 'induced'... (yes, induced can mean that as in the general definition of coming from somewhere to somewhere else is 'induced', but there is a term of 'induction', which is slightly different and more specific)
but voltage is a measurement of difference of potential... for atoms or electrons to go or be higher then somewhere else... if given the sufficient conductive properties of voltage/resistance, etc, you can measure or feel it...
yes, i know, totally basic... but...not everyone may understant some terms as they get used differently by different people and in different areas... and I am not the best person to use the most appropriate term.. but, i am confused with your use of 'induction'...
http://en.wikipedia.org/wiki/Electromagnetic_induction
typically it is involves electromagnatism, and earlier you mentioned photonic... which is also correct... but, i dont think it is either that you are mentioning as touching and getting shocked by the reflectors...
and it certainly isnt related to the 'stray' voltage that is bantered about in this and other threads..
this also relates to Bigdaddy and electrical wiring codes and the specific references to the main ground rod... and specifically, which hasnt been mentioned in this thread, the use of a 'second ground rod'... or ground point, WHICH SHOULD NEVER BE DONE... unless at the same location as the first and then bonded to the main ground bar...
at one time, i had advocated the use of a second ground bar at the fish tank... and grounding the ground probe to that....and that would be the best 'safety' method to prevent you from getting shocked but that would also totally make the rest of your house unsafe...and lead to damage of sensitive elctronics....
but this goes back to the point of what or how the purpose of the ground probe... It may 'help' in the gfi tripping.. but the main purpose is as advertised, and that is to give the 'stray' voltage a path which is less resistant than you, should you touch the water and something else which maybe grounded
when you touch the reflector and the water, (or something else), you dont know if the 'voltage' is coming from the reflector or going to the reflector... what you know is that you have created a circuit...
the question lies in if you didnt complete the circuit, would the 'stray voltage' exhist???? and the answer is no... or, if it did, the 'other path' has a significantly higer resistance...
the burning question i had and hopes would be addressed, is, if there is no circuit, and you only have one wire in the tank, will that cause damage? will the fish be affected? and i still say, NO...
and if you intentionally add one wire, (the ground probe), and then have a heater burn up/crack, or some other problem, then you will have a circuit for sure...and if you have more voltage then ground path, then the fish and corals will get zapped...as they are 'in a parallel circuit'.... maybe not as resistant or maybe less... either way, they are getting shocked for sure..
so, i kinda advocate to NOT USE ground probe....
as for the drs office and other areas that you feel the shock/buzz, you can figure out where it is coming from and then figure out how to properly ground it so the electricity goes to the correct path and not to you or other folks who may feed the tank or inadvertantly get zapped.
newer construction is good and all that but it is still possible to create a 'better/a less resistant path' to ground then the wire...and although it maybe grounded properly, you can be in a parallel circuit too... that is, ir you have two wires going to a motor, an dyou touch one side of the motor, and then touch the other side of the motor, the motor will still keep getting voltage, and so will you, and the motor will spin slower depending on how much or little resistance you offer, it's like putting a resistor across the motor connection... same thing.. bigger resistor, and it is like infinite resistance, or an open wire, and the motor spins just as fast as without it, and the smaller the resistance, the motor will slow down as the electrons go thru the resistor rather then the motor windings...
if you have less resistance then air and the wire back to the ground bar, you will feel the buzz... so this depends on humidity, where you are standing, what kinda of foot wear,, etc....
the fix... give it a better path to the ground bar...then what you are standing on, etc...
anyways. like i said earlier. i know i couldnt do this easily or concisely.. and hopefully i did it so someone can understand and tell me i am over thiniking it or somethng. and or are off base completely, or partially right or mostly wrong.. whatever....
for now. i dont use ground probes... and have gfci as far upstream as possible for most of the equipment except the main pump...