Improved Pool Venturi Jet printed in PETG designed to inject air into the pool and raise the PH even if using a solar cover. Uses nearly ideal venturi angles and ratios. Very effective air injection.  This is an improvement over my previous model was just a hipshot at trying to make a venturi work (https://www.printables.com/model/1008580-pool-jet-venturi).  

This one is louder and works much more effectually but it also sticks further into the pool.