I need to get an aerator built into my in ground pool. I was already to get this project down last weekend. Stuck my hand down in pool to feel the jet had a thread inside it. I had assumed 1,5 inches. Went to Home Depot and bought all the pvc I need to make one of these elbow jets you can buy from amazon.com. Turns out the 1,5 pipe did not fit so I went back and grabbed a 1.25 and 1 inch to down size it to no luck. Turns out the thread actual is further into the jet and there is a smooth ID surface to the outside (towards pool) that is seems to be same ID as min thread ID. Thus I can't screw anything into my jet. I have attached a picture and let me know if this looks odd or familiar.
Maybe I am going about this all wrong.