Is anyone using the Kasco Robust aire diffuser? I currently have a Gast 1/3 hp running a 4-9" disc diffuser station. With the discs from Diffuser Express in the center of a 1/3 acre pond and about 8' deep. The pressure gauge at the pump reads about 4-5 psi. I am thinking about adding another location and these look interesting but a little pricey.