Quote:
Originally Posted by
Rich L 
They both amount to the same thing. A bonded component (pump, heater, etc. is tied directly to ground. Bonds are used to insure the component is grounded even though you will also have a grounded system. Most pumps come with a 3 - prong ground plug. If purchased without the plug, a similar one or a hard wire must be carried to the system ground circuit.
The problem here is lots of people cut the ground lug to accommodate older wiring or use a 'temporary' two wire extension cord. Both are illegal and the owner can be held liable for an accident when the code is ignored. Poor grounding can develop with age but that normally happens in poor installations. You should check GFCI breakers monthly and you can also buy a test plug that can trip a Master gfci from a remote location at most hardware stores. They check for proper wiring and have a button that will trip the master from a remote receptacle.
If you’re standing on wet ground and you feel an electric shock when you touch the water you’re pond isn’t effectively grounded.
Masonry ponds without an insulating coating are grounded where the rebar is continuous so the entire masonry surface is bonded.
Bonding an insulated pond is another matter. Pure water isn’t a good conductor, it becomes a conductor as the TDS is raised, so a ground at one point won’t be an effective ground at a point at the other end of the pond (or in the filter area) unless the TDS is higher than we want it to be. One limited advantage is the poor conductivity isn’t likely to carry enough current to be dangerus but would you like to test it with one of your kids? It doesn’t become a problem until we insulate the masonry surface when we coat it with an insulator.
I don’t happen to know the code in a case like that but I would think we would have to bond it in several places if the conductivity is too low. GFCI breakers trip at less than 0.030 (30 milliamperes)amperes and current becomes normally becomes lethal at a little over 0.100 ma so I would expect the GFCI to protect us. It becomes a problem at lower currents that won’t kill you directly but can cause you to have an accident or even lock your muscles so you cannot swim.
Fortunately we worry about our koi enough to want too do something about it but pond safety protects us too.