I have been looking for countless hours trying to find out how exactly the UV sterilizer is supposed to be set up in my tank. I am currently purchasing a 25w Aqua UV sterilizer for my 100g tank to put in my sump. Im not sure this is how the UV is supposed to be placed, but from my understanding, the UV is supposed to be placed on the return pump line. So the water goes through the filtration in the sump first and then once the water is shot out of the return pump back into the display tank is where the UV should go. So basically the UV sterilizer is the last piece of equipment the water goes through before returning to the tank. Is this correct I have no idea. Also what flow meter would you recommend because I was looking at the Neptune one, but I am not planning on purchasing an apex for a while. Any insight is helpful.