As was shown in section 3.2.1, the flushing of the reactor increased the H 2 conversion which indicated that the method of supplying the nutrients over the packing of the BTF has a significant effect on the conversion. An effective nutrient supply method ensures the nutrients supply to a wider section of the packing material that enables a larger active biofilm area. In this section results from the systemic investigation of three different methods of nutrient supply in a BTF setup are reported. The three options for the nutrient supply method were continuous trickling, flushing, and flooding. The term flushing is defined as a high rate of trickling for a short while and the term flooding refers to the method of filling the column with media such that all the packing is submerged. The feed gas flowrate had to be stopped during the flooding activity. The following set of trials were conducted: (i) continuous trickling at different flowrates, (ii) flushing with continuous trickling, (iii) flushing with no trickling, (iv) flooding with continuous trickling, and (v) flooding with no trickling. The routine of weekly nutrient dosing was continued during these trials ensuring the nutrient concentration levels were higher than the minimum levels estimated in section 3.2.2.