At Pyropia farms, organic acid treatments have enhanced productivity and quality by removing pest algae (such as Ulva spp. and diatoms) and reducing the occurrence of diseases. Ulva spp. attaches to the Pyropia nets competing for inorganic nutrients & space and diminishing productivity. Additionally, the presence of attached contaminants (such as diatoms and middy particles) on the Pyropia nets negatively affects the quality of Pyropia. This study investigated the effects of removing Ulva linza and washing the Pyropia yezoensis nets using an activating treatment agent (organic acid and highly saline solution) with an air bubble device. The results of measuring the dead cell ratios after treatment under different conditions showed that the dead cell ratio of U. linza did not significantly increase when the air bubble device combined the activating treatment agent with the activating treatment agent alone. When washing the P. yezoensis nets, the air bubble device was about 19-37% more effective than the activating treatment agent alone. The findings of this study suggest that the air bubble device enhances the efficacy of the activating treatment agent, resulting in the effective cleaning of the Pyropia nets.