Hello.
You could define your marker as “nothing” in your add_marker
-function. That would be something like this:
function add_marker( $marker, map ) {
// var
var latlng = new google.maps.LatLng( $marker.attr('data-lat'), $marker.attr('data-lng') );
// create marker
var marker = new google.maps.Marker({
position : latlng,
map : map,
icon : ''
});
I’m not quite sure if this is the absolutely best way to do it, but it gets the job done.