Doughboy makes a hard plum adapter. One end attaches to the skimmer or return and the other end accepts 1 1/2" PVC pipe. Two hose clamps tighten the thing up and you are hard plumbing. Doughboy is one of the few styles of skimmers that are not PVC compatible.

Here is a trick I used before the adapter became available. Take a 1 ½” male adapter. Meaning slip on one side and male threaded on the other. On the inside of the threaded end, use a utility blade and scrape out some of the insides, until it fits snuggly over your skimmer fitting. Use plenty of PVC glue and you are all set.

Later, Dennis