The Fl IAEI had a long conversation about this and the short answer is "yes" you need the grid. I expect there will be a welded wire product soon if it is not here now. Otherwise you better get a good crimper and a buttload of "listed pressure connectors".
I have heard a rumor that they might take a "square wave" pattern using one conductor.
They also say this grid must be UNDER a fiberglass spa or pool. That one I do not understand.
ROPs close this fall.
