To summarize the effects on the health-compromised MFC outputs after the applied interventions, we refer to Figure . After shear erosion of the EAB outer layers followed by a restabilization period of 10 days, Pmax and Īmax were much diminished compared to their preovershoot values. The power density curve anomaly at 25 kΩ was eliminated after removal of the outer biofilm layer due to a decrease in the settling time during the polarization test discharge profile. Therefore, we presume that the outer EAB layers formed an electrical and/or nutrient transport barrier. SEM imaging shows two strata (Supplementary Materials Section S8). The lower stratum, which contained residual EAB following shear erosion, showed more extracellular polymeric substance, indicating stresses during growth, likely related to higher electron transfer resistance after transition to an unhealthy state. The upper stratum contained bacterial cells only (no extracellular polymeric substance), indicating that after shear erosion, the EAB regrew without such stresses. Except for some debris, SEM showed that the biofilm was uniform in height and displayed no cracks or crevices, indicating that the shear erosion was experienced evenly everywhere and not through any preferential flow paths. Although it is not shown in Figure , the overshoot persisted after shear erosion but with a reduced ΔĪOS. Increasing the flow rate to QT=10 mL h -1 resulted in improvements to all figures of merit (including a further reduced ΔĪOS). Next, we applied a 4-day pre-acclimation to 3.5 kΩ followed by a standard polarization test.