My baja step was recently built at 12" deep with two bubblers. With no nozzles installed (just female threaded returns), the returning water breaks the surface approximately 1-2". That is with half the water being diverted to a rock water fall. With all the water being sent to the bubblers, it is higher and more noticeable. I've been told I can install telescoping nozzles if I want the water to shoot up higher above the waters surface, but I haven't gotten around to ordering them. I also figure I can just install a couple eyeball type nozzles in my threaded bubbler returns, to create a little more velocity to get the water higher up.