I use these ones...

https://www.amazon.com/RealPlus-Stone-Bubbler-Aquarium-Hydroponics/dp/B08NK2HX3M

I like them because they're heavy enough to stay on the bottom without suction cups, and soak them in either a H2O2 or bleach solution between runs to sterilize them. 36 of them is going to be a little expensive, though.