Diffuser Maintenance - Tech Talk 121
Just as maintenance is important for your home and your car, your aeration system requires some upkeep. Your diffusers are constantly exposed to an organically rich environment and are going to have buildup. Unfortunately, they can't be expected to clean themselves. The good news: An annual inspection plan is all it takes for you to rest assured your system is running optimally.
Rubber diffuser membranes consist of many tiny holes that open as air passes through and close when airflow ceases. This process prevents water from entering the unit. However, when compressed air is introduced into water, as in aeration, calcium carbonate (CaCO3) forms a hard crust on the diffuser surface. The calcium buildup on these small openings forces the rubber to stretch in order to continue to diffuse air, leading to an inability to go back to its original size for the rubber (called memory loss). This results in larger bubble size and a less efficient diffuser.
Glass-bonded silica diffusers may become infused with bacteria, other organics and mineral deposits such as calcium carbonate, causing unnecessary back pressure on the compressor or blower over time. If this back pressure persists, it can dramatically increase wear and tear and, in turn, shorten the life of the compressor.
Whether or not a diffuser is operating unobstructed is impossible to tell by simply looking at the bubble plume. It may be apparent if the rising bubbles are noticeably larger, but this is not always the case. There is only one way to be sure the diffusers are free of obstructions—remove them from the water and take a look. Whether you use glass-bonded silica or rubber membranes, it is imperative they are checked at least once a year to determine if cleaning is necessary. If needed, undiluted muriatic acid can be used for both kinds of diffusers. See Tech Talk 53 for more information.