Diffuser Airstone 7"
Starts at: $74.28
Brand: Outdoor Water Solutions
Manufactured with a large base to insure the stone is sealed to the base correctly, forcing air out of the micro-pores in the stone.
If holes are too big, bubbles are too big; if holes are too small, bubbles are too small.
This stone has proven itself for over 20 years and is very popular.
Backflow Valve included to keep waste from backing up the airline.