I called my idea 'silly' as a way to downplay it. Call it modesty. There's no harm in doing so, but there is no code requirement - yet! Were this a pool, then there would be a requirement for an 'equipotential grid.'
I'm not aware of any conduit that requires support every three feet. Though, as my earlier description of using strut made clear, I encourage supporting conduit in excess of 'code minimums' where I believe the conduit will be subject to additional loading ... as when a kid climbs on it!
"Stray voltage" and "transient voltage" are terms sometimes used to describe folks getting shocks while swimming. These instances have almost always involved three things:
1) CLEAN fresh water;
2) A pool shell that was effectively insulated from the ground around the pool; and,
3) A municipality-owned electrical utility that was using the earth as a return path for it's various transformers.
The NEC adopted a few things in an attempt to address these issues. The first was to make an equipotential plane around the pool. The next was to require you to "bond" the water, by bonding a piece of metal that was in contact with the pool water.
