that is a bad approach , that is a loop per arrow .

use one main loop that removes one arrow every n-seconds/ticks/frame from a list/array which you use to manage your arrow storage/reference .

eg .

if ( current_time >= remove_arrow_time)
{
if (myarrowlist.itemscount>0)
{
myarrowlist.remove(0);//remove first item in list
}
}

or better yet is to use a frame count instead of time

.