regular does work but IMO I would use the blue color specifically made for spa flex I have had a few connections that didn't seed just right using the thiner regular pvc glue, if you have nothing else and are in a pinch go for it with the regular, if you are not in a pinch and going to HD to pick up supplies then I can see no reason why you would not pick up the glue made specifically for spa flex unless you are worried about the dollar or two more in cost and in that case you shouldn't be in this hobby