Yes there are people who use multiple hob filters. Maintenance and appropriate wc's will be needed.Does anyone ever put 3 ac110's on a tank this large. What would 3 of those do on a 150gal? I was thinking 3 spaced out woyld cover the length of the tank and I'm trying to do the math with actual flow rates and it seems that 2-3 ac110's would cover the requirements of a 150gal unplanted tank. Am I on the right track?