For maximum oxygen transfer at low cost we recommend fine bubble tube diffusers. They have a special non-buyoant design ensuring diffusion occurs evenly. Membranes are made of urethane or other materials on request. The diffuser body is made of PVC and the membrane is attached to the diffuser body with two stainless steel clamps. A built-in triple check valve prevents waste water from entering the diffuser and piping system. Disc diffusers can be used to supplement existing tube diffusers or as an efficient low-cost alternative.