I have a typical Florida pool/spa setup. In the spa I used to have a water feature which I didn’t care for. It causes uneven flow back into the pool. It was screwed into the floor of the spa via PVC. I removed it and at night when the pump stops, the spa level drops by half. Is there a type of fitting I can put in the 2” ground fitting on the spa floor which will open when there’s water flow and close when there isn’t? Thanks!